U.S. patent application number 11/117549 was filed with the patent office on 2005-08-25 for optical disk, optical disk recording and reproducing apparatus, method for recording, reproducing and deleting data on optical disk, and information processing system.
Invention is credited to Ishida, Takashi, Ishihara, Hideshi, Ito, Motoshi, Jahana, Tadashi, Nagai, Takahiro, Nakamura, Atsushi, Nakata, Kouhei, Ohara, Shunji, Oshima, Mitsuaki, Shoji, Mamoru, Takagi, Yuji, Yumiba, Takashi.
Application Number | 20050185547 11/117549 |
Document ID | / |
Family ID | 27314391 |
Filed Date | 2005-08-25 |
United States Patent
Application |
20050185547 |
Kind Code |
A1 |
Nagai, Takahiro ; et
al. |
August 25, 2005 |
Optical disk, optical disk recording and reproducing apparatus,
method for recording, reproducing and deleting data on optical
disk, and information processing system
Abstract
A recording type optical disk on which data is recordable
includes a data recording and reproducing area for recording data
therein and reproducing data therefrom, and a read-only disk
identification information area for recording disk identification
information for identifying the optical disk therein. In the
optical disk, the disk identification information is formed by
removing a reflection film that is formed on the optical disk in a
strip shape. The disk identification information includes an
inherent disk identifier for each optical disk, and the data
recording and reproducing area includes an area for recording
encrypted data therein. The encrypted data is encrypted by using
information including the disk identification information for
identifying the optical disk as a key.
Inventors: |
Nagai, Takahiro; (Osaka,
JP) ; Ishihara, Hideshi; (Osaka, JP) ; Takagi,
Yuji; (Osaka, JP) ; Yumiba, Takashi; (Kyoto,
JP) ; Shoji, Mamoru; (Osaka, JP) ; Oshima,
Mitsuaki; (Kyoto, JP) ; Ohara, Shunji; (Osaka,
JP) ; Ito, Motoshi; (Osaka, JP) ; Ishida,
Takashi; (Kyoto, JP) ; Nakamura, Atsushi;
(Osaka, JP) ; Jahana, Tadashi; (Kanagawa, JP)
; Nakata, Kouhei; (Hyogo, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
27314391 |
Appl. No.: |
11/117549 |
Filed: |
April 29, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11117549 |
Apr 29, 2005 |
|
|
|
09560563 |
Apr 28, 2000 |
|
|
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Current U.S.
Class: |
369/47.55 ;
369/30.3; 369/44.27; G9B/19.017; G9B/19.018; G9B/20.002;
G9B/23.087; G9B/23.09; G9B/23.091; G9B/7.033; G9B/7.034 |
Current CPC
Class: |
G11B 20/00304 20130101;
G11B 7/263 20130101; G11B 20/00333 20130101; G11B 20/00268
20130101; G11B 23/34 20130101; G11B 20/00528 20130101; G11B 20/0084
20130101; G11B 23/36 20130101; G11B 7/00745 20130101; G11B 23/284
20130101; G11B 7/00736 20130101; G11B 19/122 20130101; G11B
20/00115 20130101; G11B 20/00181 20130101; G11B 20/00224 20130101;
G11B 20/00768 20130101; G11B 7/0037 20130101; G11B 20/1217
20130101; G11B 20/00094 20130101; G11B 20/00492 20130101; G11B
20/00557 20130101; G11B 20/00311 20130101; G11B 20/00347 20130101;
G11B 20/00086 20130101; G11B 20/00666 20130101; G11B 23/281
20130101; G11B 19/12 20130101; G11B 7/24038 20130101; G11B 20/0021
20130101 |
Class at
Publication: |
369/047.55 ;
369/030.3; 369/044.27 |
International
Class: |
G11B 007/004 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 28, 1999 |
JP |
P11-122104 |
May 10, 1999 |
JP |
P11-128197 |
Oct 21, 1999 |
JP |
P11-299635 |
Claims
What is claimed is:
1. An optical disk recording and reproducing apparatus for
controlling at least one of: (a) a recording operation for
recording data in a data recording and reproducing area of an
optical disk of recording type on which data is recordable, and (b)
a reproducing operation for reproducing data from the data
recording and reproducing area, wherein said optical disk includes
a disk identification information area for recording therein disk
identification information for identifying said optical disk, and
wherein said optical disk recording and reproducing apparatus
comprises; reproducing means for reproducing said disk
identification information from said disk identification
information area; and control means for judging whether or not at
least one of the recording operation and the reproducing operation
is performed based on the reproduced disk identification
information, and for controlling said optical disk recording and
reproducing apparatus to perform at least one of the recording
operation and the reproducing operation in response to a judgment
result.
Description
[0001] This application is a Divisional of Ser. No. 09,560/563,
filed Apr. 28, 2000, now allowed.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an optical disk, an optical
disk recording and reproducing apparatus, a method for recording,
reproducing and deleting data on an optical disk, and an
information processing system. In particular, the present invention
relates to an optical disk, an optical disk recording and
reproducing apparatus, a method for recording, reproducing and
deleting data on an optical disk, and an information processing
system which can prevent unauthorized digital copying from being
performed from an optical disk, on which data such as AV data
(Audio and Visual Data) including image data of movies and audio
data of music which are protected with copyrights is recorded, to
another recording media such as an optical disk of another
recording type or the like.
[0004] 2. Description of the Related Art
[0005] An optical disk is superior in random accessibility to
conventional tape media, and has such an advantage in that
deterioration of the optical disk due to repetitive use is reduced
because of being capable of non-contacting recording and
reproducing by using a laser light. Further, the optical disk has
such an advantage in that the optical disk can be mass produced at
low cost by mastering performed by disk manufacturers, and a CD
(Compact Disc) becomes generalized as a high quality digital audio
instead of a conventional phonograph record for analog recording.
Furthermore, a DVD (Digital Video Disk or Digital Versatile Disk)
on which high quality image data has been digitally recorded has
recently been commercialized, and the optical disk will be expected
to be further developed as a digital recording medium for AV data
in the near future.
[0006] On the other hand, in addition to a read-only optical disk
on which data has been previously recorded in a pre-pit form by a
disk manufacturer, such as a music CD, CD-ROM, DVD-ROM or the like,
an optical disk of recording type (a recording type optical disk)
on which a user can record AV data at home, such as CD-R, CD-RW,
MO, MD, DVD-RAM or the like has been recently developed and has
become widespread.
[0007] Also, in television broadcasts, digital systems for allowing
multi-channeling or various services have been introduced instead
of conventional analog systems, and such a trend will increase in
the near future. In particular, the optical disk of recording type
is expected to be utilized as recording media of content which is
delivered through digitized broadcasting or communication for
recording AV data which is mainly for the purpose of time shift
utilization where, after contents are accumulated upon being
delivered, a program selection is performed and the selected
content is listened to or watched.
[0008] Conventionally, an optical disk of recording type which has
been utilized mainly for computers is utilized for storing data
which has been created by a user himself, and the optical disk of
recording type does not have any means for preventing copying from
being performed between two or more recording type optical disks.
When the optical disk of recording type is widely utilized, an
ordinary user copies recorded data of an optical disk to another
optical disk of recording type irregularly as it is so that it
becomes possible to obtain an unjust reproduction without paying
the copyright royalty that is to be paid to an author or writer of
the copied AV data and without any deterioration in the sound
quality and image quality of the copied AV data because the optical
disk of recording type is digitally recordable, which becomes a
factor in preventing the spread of excellent content. Regarding an
MD (Magentic Disk) on which music or the like is digitally
recorded, means for performing generation management for limiting
the number of recordings has been introduced where data, together
with generation management data, is recorded on an optical disk and
the number of permissible times the data can be copied is limited
by the generation management data.
[0009] Also, in order to prevent the unjust copying of a CD-ROM or
a DVD-ROM, for example, a method for forming a Burst Cutting Area
(hereinafter referred to as a BCA), which is a write once area for
overwriting a barcode on a pit section of an optical disk, and for
recording respective disk IDs of each of the optical disks on the
BCA which are different from each other and are assigned for each
optical disk when the optical disks are manufactured has been
proposed in an international application of International
Publication No. WO 97/14144. According to this method, since a
password is different for each disk ID, one password can decrypt
only a cipher of one disk, and therefore, even when content is
copied unjustly, the content cannot be decrypted due to the lack of
information of a disk ID.
[0010] FIG. 39 is a block diagram showing a configuration of a user
data area of a conventional DVD-ROM, and a configuration of an
optical disk reproducing apparatus for decrypting an encrypted
content from data in the user data area. In the DVD-ROM, as shown
in FIG. 39, encryption is performed on content data that is
recorded on a disk.
[0011] Referring to FIG. 39, the user data area of the DVD-ROM is
constituted by a sector header area 3201, a main data area 3202,
and an error detection code 3203. In this case, a sector address
3204 indicating a position of a sector, copyright control
information 3205 on which the copyright control information
regarding data that is recorded on the main data area 3202 (for
example, a scramble flag, copy control information and the like) is
recorded, and a decipher key 3206 for decrypting a cipher when the
cipher is performed on data that is recorded on the main data area
3202 are each recorded on the sector header area 3201. Also, mainly
AV data that are required for copyright protection and the like are
encrypted and recorded on the main data area 3202.
[0012] At the time of reproducing such a user data area, a decipher
key 3206 which is required for reproducing encrypted content from
the sector header area 3201 is first acquired. The acquired
decipher key 3206 is inputted to a key decrypting device 3207. The
key decryption device 3207 decrypts the inputted decipher key 3206
into a content decipher key by using a predetermined disk key, and
outputs the content decipher key to a decrypting device 3208. Next,
the decrypting device 3208 decrypts the encrypted content of the
main data area 3202 by using the decrypted content decipher key
according to the copyright control information 3205 which has been
stored on the sector header area 3201 corresponding to the main
data area 3202, and then, the decrypted content which is
reproducible data can be obtained.
[0013] In the optical disk according to the configuration shown in
FIG. 39, it is possible to perform reading-out from the main data
area 3202 through a driving apparatus of a personal computer or the
like. However, an unjust reproduction or a production of a pirated
version can be prevented by constituting the optical disk so that
an area where the decipher key 3206 is recorded can be read out
only by an optical disk reproducing apparatus with a regular
authentication function.
[0014] However, for the unjust copying preventing method using the
generation management data, the generation management data will be
inevitably changed upon copying (i.e., changed from "once copying
possible" to "copying impossible"). On the other hand, there is a
problem in that unjust copying cannot be prevented sufficiently by
copying data on the optical disk together with the generation
management data without changing the generation management data or
by altering the generation management data by a computer or the
like and recording the data and the generation management data on
the optical disk. Furthermore, since the number of permissible
copies is limited based on the generation management data which has
been previously recorded together with the content, there is a
problem in that, even when a regular copyright royalty is paid,
data which has been designated as "copying impossible" is not
allowed to be copied to another optical disk at all, and a user
must therefore wait for a content provider to provide the user with
content data. Both of the above-described problems are caused
because the content provider cannot manage content copying onto an
optical disk of recording type performed by a user
sufficiently.
[0015] Recently, personal computers are further improved in
performance and they are also connected to networks so that cipher
decryption can be performed at high speeds by a plurality of
personal computers. In order to further increase the robustness of
the cipher against such a decryption, it becomes necessary to
extend a key length of a key which is used for the cipher. However,
in a key management method for recording a decipher key in a sector
header as is conventionally proposed, there is a problem in that
only a decipher key with a size of a predetermined length (a size
of decipher key area) or less is recorded, and a key length cannot
be elongated for the purpose of improving the robustness of a
cipher in the future.
SUMMARY OF THE INVENTION
[0016] The first object of the present invention is to provide an
optical disk, an optical disk recording apparatus, an optical disk
reproducing apparatus, an optical disk recording and reproducing
apparatus, a method for recording and reproducing data on an
optical disk, a method for recording data on an optical disk, a
method for reproducing data on an optical disk, a method for
deleting data on an optical disk, and an information processing
system which can prevent the unjust digital copying which a content
provider cannot manage.
[0017] Also, the second object of the present invention is to
provide an optical disk, an optical disk recording apparatus, an
optical disk reproducing apparatus, an optical disk recording and
reproducing apparatus, a method for recording and reproducing on an
optical disk, a method for recording on an optical disk, a method
for reproducing on an optical disk, a method for deleting data on
an optical disk, and an information processing system which can
enhance the reliability of a decipher key that is required to
decrypt data which is required for copyright protection.
[0018] Furthermore, the third object of the present invention is to
provide an optical disk, an optical disk recording apparatus, an
optical disk reproducing apparatus, an optical disk recording and
reproducing apparatus, a method for recording and reproducing data
on an optical disk, a method for recording data on an optical disk,
a method for reproducing data on an optical disk, a method for
deleting data on an optical disk, and an information processing
system which can set the robustness level of a cipher according to
a level of copyright protection of content to be recorded.
[0019] In order to achieve the aforementioned objects, according to
a first aspect of the present invention, an optical disk of
recording type on which data is recordable is provided. The optical
disk of the first aspect includes a data recording and reproducing
area for recording data therein and reproducing data therefrom,
and
[0020] a read-only disk identification information area for
recording disk identification information for identifying the
optical disk therein.
[0021] In the above-mentioned optical disk, the disk identification
information is preferably formed by removing a reflection film that
is formed on the optical disk in a strip shape.
[0022] In the above-mentioned optical disk, the disk identification
information preferably includes an inherent disk identifier for
each optical disk.
[0023] In the above-mentioned optical disk, the data recording and
reproducing area preferably includes an area for recording
encrypted data therein, where the encrypted data is encrypted by
using information including the disk identification information for
identifying the optical disk as a key.
[0024] In the above-mentioned optical disk, the encrypted data
preferably includes content data which is at least one of image
data and music data.
[0025] In the above-mentioned optical disk, the encrypted data
preferably includes a descramble key for decrypting a cipher which
has been performed on content data.
[0026] In the above-mentioned optical disk, the encrypted data
preferably includes a descramble key for decrypting a cipher which
has been performed on content data, and an error detection code for
detecting an error in the descramble key.
[0027] According to a second aspect of the present invention, there
is provided an optical disk of recording type on which data is
recordable,
[0028] wherein the optical disk includes a data recording and
reproducing area for recording data therein and reproducing data
therefrom, and
[0029] wherein the data recording and reproducing area includes an
area for recording therein content data which is at least one of
encrypted image data and encrypted music data, and a descramble key
for decrypting a cipher which has been performed on the content
data.
[0030] According to a third aspect of the present invention, there
is provided an optical disk of recording type on which data is
recordable. The optical disk of the third aspect includes:
[0031] a read-only disk identification information area for
recording therein disk identification information for identifying
the optical disk;
[0032] a data recording and reproducing area for recording therein
and reproducing therefrom content data including at least one of
encrypted image data and encrypted music data; and
[0033] a key management information area for recording therein key
information that is used when reproducing the content data, and a
descramble key which is encrypted by using the disk identification
information as a key.
[0034] According to a fourth aspect of the present invention, there
is provided an optical disk recording and reproducing apparatus for
controlling at least one of:
[0035] (a) a recording operation for recording data in a data
recording and reproducing area of an optical disk of recording type
on which data is recordable; and
[0036] (b) a reproducing operation for reproducing data from the
data recording and reproducing area,
[0037] wherein the optical disk includes a disk identification
information area for recording therein disk identification
information for identifying the optical disk.
[0038] The optical disk recording and reproducing apparatus of the
fourth aspect comprises:
[0039] reproducing means for reproducing the disk identification
information from the disk identification information area; and
[0040] control means for judging whether or not at least one of the
recording operation and the reproducing operation is performed
based on the reproduced disk identification information, and for
controlling the optical disk recording and reproducing apparatus so
as to perform at least one of the recording operation and the
reproducing operation in response to a judgment result.
[0041] According to a fifth aspect of the present invention, there
is provided an optical disk recording apparatus for recording
content data on an optical disk of recording type on which data is
recordable,wherein the optical disk includes an area for recording
a disk identification information area for identifying the optical
disk.
[0042] The optical disk recording apparatus of the fifth aspect
comprisesreproducing means for reproducing the disk identification
information from the disk identification information area, and
recording means for recording at least partially encrypted data on
the optical disk by using the reproduced disk identification
information as a key.
[0043] According to a sixth aspect of the present invention, there
is provided an optical disk reproducing apparatus for reproducing
content data from an optical disk of recording type on which data
is recordable wherein the optical disk includes a disk
identification information area for recording therein disk
identification information for identifying the optical disk.
[0044] The optical disk reproducing apparatus of the sixth aspect
comprises reproducing means for reproducing the disk identification
information from the disk identification information area, and
decrypting means for decrypting at least partially encrypted data
by using the reproduced disk identification information as a key
after reproducing the at least partially encrypted data from the
optical disk.
[0045] According to a seventh aspect of the present invention,
there is provided an optical disk recording and reproducing method
for controlling at least one of:
[0046] (a) a recording operation for recording data into a data
recording and reproducing area of an optical disk of recording type
on which data is recordable; and
[0047] (b) a reproducing operation for reproducing the data from
the data recording and reproducing area,
[0048] wherein the optical disk includes a disk identification
information area for recording therein disk identification
information for identifying the optical disk, and
[0049] The method of the seventh aspect includes the steps of:
[0050] reproducing the disk identification information from the
disk identification information area; and
[0051] judging whether or not at least one of the recording
operation and the reproducing operation is performed based on the
reproduced disk identification information, and controlling the
recording operation and the reproducing operation so as to perform
at least one of the recording operation and the reproducing
operation based on a judgement result.
[0052] According to an eighth aspect of the present invention,
there is provided an optical disk recording method for recording
content data on an optical disk of recording type on which data is
recordable, wherein the optical disk includes a disk identification
information area for recording therein disk identification
information for identifying the optical disk.
[0053] The method of the eighth aspect includes the steps of
reproducing disk identification information from the disk
identification information area, and recording at least partially
encrypted data on the optical disk by using the reproduced disk
identification information as a key.
[0054] According to a ninth aspect of the present invention, there
is provided an optical disk reproducing method for reproducing
content data from an optical disk of recording type on which data
is recordable wherein the optical disk includes a disk
identification information area for recording therein disk
identification information for identifying the optical disk.
[0055] The method of the ninth aspect includes of the steps of
reproducing the disk identification information from the disk
identification information area, and
[0056] decrypting at least partially encrypted data by using the
reproduced disk identification information as a key after
reproducing the at least partially encrypted data.
[0057] According to a tenth aspect of the present invention, there
is provided an optical disk of recording type on which data is
recordable. The optical disk of the tenth aspect includes a first
information area for recording first disk information therein, a
second information area for recording therein second disk
information for identifying each optical disk, and a user data area
for recording information data by irradiating a light beam onto the
user data area.
[0058] According to an eleventh aspect of the present invention,
there is provided an optical disk of recording type on which data
is recordable, wherein the optical disk has a sector structure
comprising a plurality of sectors, wherein each of the plurality of
sectors includes a sector header area and a main data area for
recording encrypted data therein, wherein the sector header area
includes a decipher key information area for recording therein at
least one decipher key that is required for decrypting the
encrypted data, and wherein a size of the decipher key information
area is smaller than the size of each decipher key.
[0059] According to a twelfth aspect of the present invention,
there is provided an optical disk of recording type on which data
is recordable,
[0060] wherein the optical disk includes a main data area for
recording data therein,
[0061] wherein the main data area includes a non-encrypted area for
recording data in a non-encrypted status, and an encrypted area for
recording data in an encrypted status,
[0062] wherein the non-encrypted area includes decipher key
conversion data used for converting a decipher key for decrypting
data into a converted decipher key, and
[0063] wherein data in the encrypted area is encrypted by using the
converted decipher key.
[0064] According to a thirteenth aspect of the present invention,
there is provided an optical disk recording method for recording
data on an optical disk of recording type on which data is
recordable. The method of the thirteenth aspect includes the steps
of:
[0065] reading out a decipher key status which is recorded on the
optical disk, and judging whether or not there is an empty area for
a decipher key based on the read-out decipher key status;
[0066] reserving a decipher key area and recording the decipher key
in the decipher key area when judging that there is the empty area
for the decipher key;
[0067] setting copyright control information and a decipher key
index in at least one unit of a file unit and an extent unit;
[0068] encrypting data by using the decipher key, and recording the
encrypted data on the optical disk in at least one unit of a file
unit and an extent unit; and
[0069] recording, on the optical disk, optical disk file management
information for managing data which is recorded on the optical
disk.
[0070] According to a fourteenth aspect of the present invention,
there is provided an optical disk reproducing method for
reproducing data from an optical disk of recording type on which
data is recordable. The method of the fourteenth aspect includes
the steps of reproducing and acquiring a decipher key index from a
data recording area in which data to be reproduced is recorded in a
file unit or an extent unit,reproducing and acquiring a decipher
key corresponding to the acquired decipher key index, and
reproducing data in the file unit or the extent unit which is
encrypted by using the decipher key.
[0071] According to a fifteenth aspect of the present invention,
there is provided an optical disk deleting method for deleting data
from an optical disk of recording type on which data is recordable.
The method of the fifteenth aspect comprises:
[0072] reproducing and acquiring a decipher key index from a
recording area in which data to be deleted is recorded in a file
unit or an extent unit;
[0073] updating a decipher key status, which corresponds to the
acquired decipher key index and which indicates a recorded status
of a decipher key, and releasing the decipher key; and
[0074] updating file management information for managing data which
is recorded on the optical disk by deleting a file entry
corresponding to the data to be deleted from the file management
information.
[0075] According to a sixteenth aspect of the present invention,
there is provided an information processing system comprising a
data encrypting apparatus for encrypting data by using a cipher
key, an optical disk recording and reproducing apparatus for
recording a decipher key that is required for decrypting data on an
optical disk of recording type, and for reproducing the recorded
decipher key, and a control apparatus which is connected to the
optical disk recording and reproducing apparatus and the data
encrypting apparatus.
[0076] The optical disk recording and reproducing apparatus of the
seventeenth aspect comprises:
[0077] first recording and reproducing means for recording a
decipher key table on the optical disk, and for reproducing the
decipher key table from the optical disk;
[0078] encrypting and decrypting means for encrypting the decipher
key, for transmitting the encrypted decipher key, for receiving the
encrypted decipher key from the control apparatus, and for
decrypting the encrypted decipher key; and
[0079] second recording and reproducing means for recording a
decipher key status table for indicating a recorded status of the
decipher key on the optical disk, and for reproducing the decipher
key status table from the optical disk.
[0080] The data encrypting apparatus of the seventeenth aspect
comprises encrypting means for encrypting the decipher key, and
transmitting the encrypting decipher key to the control
apparatus.
[0081] The control apparatus of the seventeenth aspect comprises:
receiving means for receiving the encrypted decipher key from the
encrypting means of the data encrypting apparatus; and
[0082] allocating means for searching for an empty area for the
decipher key based on the reproduced decipher key status table, for
allocating the received and encrypted decipher key into the
searched empty area, and for transmitting the allocated and
encrypted decipher key to the optical disk recording and
reproducing apparatus.
[0083] The encrypting and decrypting means of the optical disk
recording and reproducing apparatus receives the allocated and
encrypted decipher key from the allocating means of the control
apparatus, and decrypts the received encrypted decipher key.
[0084] According to an eighteenth aspect of the present invention,
there is provided an optical disk of read-only type for reproducing
recorded data. The optical disk of the eighteenth aspect includes a
data reproducing area for recording data therein, and a read-only
disk identification information area for recording therein disk
identification information for identifying the optical disk.
[0085] The data reproducing area of the optical disk of the
eighteenth aspect includes an area in which data is recorded that
is encrypted by using information including the disk identification
information for identifying the optical disk as a key.
BRIEF DESCRIPTION OF THE DRAWINGS
[0086] These and other objects and features of the present
invention will become clear from the following description when
taken in conjunction with the preferred embodiments of the present
invention with reference to the accompanying drawings throughout
which like parts are designated by like reference numerals, and in
which:
[0087] FIG. 1 is a plan view illustrating a data recording area of
an optical disk of recording type 100 of a first preferred
embodiment according to the present invention;
[0088] FIG. 2A shows a block diagram and a cross section view
illustrating an apparatus configuration for forming a BCA 106 on
the optical disk 100 shown in FIG. 1;
[0089] FIG. 2B shows a cross section view of the optical disk 100
after formation of the BCA 106 on the optical disk 100 shown in
FIG. 1, and a graph showing a strength of a reflected light in the
horizontal direction;
[0090] FIG. 3 is a diagram showing a recording format of the BCA
106 shown in FIG. 1;
[0091] FIG. 4 is a diagram for illustrating a sector structure of
sector data 401 within a user data area 102 shown in FIG. 1;
[0092] FIG. 5 is a diagram illustrating a configuration of a key
management information area 107 shown in FIG. 1;
[0093] FIG. 6A is a block diagram showing a recording method for
recording a descramble key and AV data in the sector data 401 shown
in FIG. 1 according to a modified preferred embodiment of the first
preferred embodiment;
[0094] FIG. 6B is a block diagram showing a recording method for
recording a key index to the descramble key and the AV data into
the sector data 401 shown in FIG. 1 according to the first
preferred embodiment;
[0095] FIG. 7 is a block diagram showing a configuration of an
optical disk recording and reproducing apparatus of a second
preferred embodiment according to the present invention;
[0096] FIG. 8 is a flowchart showing a recording process of AV data
which is performed by a control CPU 710 of the optical disk
recording and reproducing apparatus shown in FIG. 7;
[0097] FIG. 9 is a flowchart showing an allocating process of a key
management information area which is performed by the control CPU
710 of the optical disk recording and reproducing apparatus shown
in FIG. 7;
[0098] FIG. 10 is a flowchart showing a recording process of a
descramble key which is performed by the control CPU 710 of the
optical disk recording and reproducing apparatus shown in FIG.
7;
[0099] FIG. 11 is a flowchart showing a reproducing process of AV
data which is performed by the control CPU 710 of the optical disk
recording and reproducing apparatus shown in FIG. 7;
[0100] FIG. 12 is a flowchart showing an acquiring process of a
descramble key which is performed by the control CPU 710 of the
optical disk recording and reproducing apparatus shown in FIG.
7;
[0101] FIG. 13 is a block diagram showing a method for determining
whether or not a descramble key is regular based on an encrypted
descramble key according to a modified preferred embodiment of the
first preferred embodiment;
[0102] FIG. 14 is a diagram showing a configuration of the
descramble area management table according to a modified preferred
embodiment of the first preferred embodiment;
[0103] FIG. 15A is a diagram showing whether or not copying or
reproducing of contents is possible within the same region or in
different regions in a case where a region identifier is recorded
when a content is recorded in the first preferred embodiment;
[0104] FIG. 15B is a diagram showing whether or not copying or
reproducing of the content is possible in the same region or in
different regions in a case where a region identifier is previously
recorded when an optical disk is shipped in the first preferred
embodiment;
[0105] FIG. 16 is a plan view showing a data recording area of an
optical disk 1101 of a third preferred embodiment according to the
present invention;
[0106] FIG. 17 is a waveform diagram showing signal waveforms of a
reproduced signal 1201 and a reproduced binarized signal 1207 in a
BCA reproducing circuit 1401 according to the third preferred
embodiment;
[0107] FIG. 18 is a block diagram showing a configuration of the
BCA reproducing circuit 1401 according to the third preferred
embodiment;
[0108] FIG. 19 is a block diagram showing a configuration of an
optical disk recording and reproducing system according to the
third preferred embodiment;
[0109] FIG. 20 is a block diagram showing a configuration of an
optical disk recording and reproducing system of a fourth preferred
embodiment according to the present invention;
[0110] FIG. 21 is a plan view showing a data recording area of an
optical disk 1601 of a fifth preferred embodiment according to the
present invention;
[0111] FIG. 22 is a block diagram showing a configuration of an
optical disk recording and reproducing system according to the
fifth preferred embodiment;
[0112] FIG. 23 is a table showing a configuration of an ID adding
table according to the fifth preferred embodiment;
[0113] FIG. 24 is a plan view showing a data recording area of an
optical disk 1101a according to a modified preferred embodiment of
the third preferred embodiment;
[0114] FIG. 25 is a plan view showing a data recording area of an
optical disk 1601a according to a modified preferred embodiment of
the fifth preferred embodiment;
[0115] FIG. 26 is a block diagram showing a configuration of a user
data area 2150 on the optical disk, and a configuration of an
optical disk reproducing apparatus for decrypting an encrypted
content from data in the user data area 2150 according to a sixth
preferred embodiment of the present invention;
[0116] FIG. 27 is a block diagram showing an arrangement of
copyright control information and decipher key into a user data
area, and an arrangement of an encrypted content into a main data
area 2102 in the optical disk according to the sixth preferred
embodiment;
[0117] FIG. 28 is a block diagram showing an arrangement of a case
where a unit for error correction is applied for a plurality of
sectors in the optical disk according to the sixth preferred
embodiment;
[0118] FIG. 29 is a block diagram showing a configuration of a
lead-in area 2401 and a user data area 2402 within an optical disk
of a seventh preferred embodiment according to the present
invention, and a configuration of an optical disk reproducing
apparatus for decrypting an encrypted content from data stored in
the lead-in area 2401 and the user data area 2402;
[0119] FIG. 30A is a block diagram showing a data configuration in
the case of indicating an unrecorded status by an initial value of
a decipher key in the main data area 2102 of the lead-in area 2401
within the optical disk according to the seventh preferred
embodiment;
[0120] FIG. 30B is a block diagram showing a data configuration in
the case of indicating a recorded status by a decipher key status
table 2502 in the main data area 2102 of the lead-in area 2401
within the optical disk according to the seventh preferred
embodiment;
[0121] FIG. 31 is a block diagram showing an arrangement of a
decipher key in the optical disk according to the seventh preferred
embodiment;
[0122] FIG. 32 is a block diagram showing a data configuration for
managing data of an optical disk by a file management system of an
eighth preferred embodiment according to the present invention;
[0123] FIG. 33 is a flowchart showing a recording process of
recording content that is required for copyright protection which
is performed by the file management system according to the eighth
preferred embodiment;
[0124] FIG. 34 is a flowchart showing a reproducing process of
reproducing content which is performed by the file management
system according to the eighth preferred embodiment;
[0125] FIG. 35 is a flowchart showing a deleting process of
deleting content which is performed by the file management system
according to the eighth preferred embodiment;
[0126] FIG. 36 is a block diagram showing a configuration of an
optical disk system of a ninth preferred embodiment according to
the present invention;
[0127] FIG. 37 is a block diagram showing a configuration of a user
data area 2150 within an optical disk of a tenth preferred
embodiment according to the present invention, a configuration of
an optical disk recording apparatus for encrypting and recording a
content into the user data area 2150, and a configuration of an
optical disk reproducing apparatus for decrypting an encrypted
content from data stored in the user data area 2150;
[0128] FIG. 38 is a block diagram showing a configuration of a user
data area 2402 within an optical disk of an eleventh preferred
embodiment according to the present invention, a configuration of
an optical disk recording apparatus for encrypting and recording a
content into the user data area 2402, and a configuration of an
optical disk reproducing apparatus for decrypting an encrypted
content from data of the user data area 2402; and
[0129] FIG. 39 is a block diagram showing a configuration of a user
data area of a DVD-ROM, and a configuration of an optical disk
reproducing apparatus for decrypting an encrypted content from data
of the user data area according to the prior art.
DETAILED DESCRIPTION OF THE INVENTION
[0130] Preferred embodiments according to the present invention
will be described below with reference to the attached
drawings.
First Preferred Embodiment
[0131] FIG. 1 shows a plan view illustrating a data recording area
of an optical disk 100 of recording type of the first preferred
embodiment according to the present invention. The optical disk 100
of recording type is a recording medium which is capable of
recording digital data, and includes a write-once type
non-rewritable optical disk and a rewritable optical disk.
[0132] Referring to FIG. 1, reference numeral 101 denotes a lead-in
area for recording management information therein for the optical
disk 100, and reference numeral 102 denotes a user data area for
recording digital data therein which needs copyright protection,
such as (a) AV data content including at least one of image data
(including still picture images and animated picture images) such
as movies or the like, and speech sound data such as music or the
like; and (b) computer software. Reference numeral 103 denotes a
lead-out area for recording defect management information or the
like therein. The lead-in area 101 is constituted by a read-only
area 104 in which data is recorded in a form of pre-pits, and a
recording and reproducing area 105 which is a rewritable area with
guide grooves. In this case, in the read-only area 104, a control
area or the like which describes physical characteristics of the
optical disk 100 is recorded in a form of pre-pits by the
manufacturer. In the lead-out area 103 and the rewritable area 105,
data for a writing test which is performed by an optical disk
recording apparatus, and management information for managing
defects on the optical disk 100 are recorded by an optical disk
recording apparatus. In addition, on the inner peripheral side of
the read-only area 104 in the lead-in area 101, a BCA 106 which is
formed as disk individual information is once written on the
optical disk 100 by the following well-known method, after
completion of the optical disk 100 on which content has been
recorded.
[0133] FIG. 2A shows a block diagram and a cross sectional view
illustrating an apparatus configuration when the BCA 106 is formed
on the optical disk 100 shown in FIG. 1, and FIG. 2B shows a cross
sectional view of the optical disk 100 and a graph showing an
intensity of reflected light in the horizontal direction after the
BCA 106 is formed on the optical disk 100 shown in FIG. 1.
[0134] Referring to FIGS. 2A and 2B, an example of the optical disk
100 of double-side recording type is shown, and the optical disk
100 is constituted so that a recording layer 202, a reflecting
layer 203, a bonding layer 204, a reflecting layer 205 and a
recording layer 206 are inserted between two substrates 201 and
207.
[0135] As shown in FIG. 2A, when the BCA is recorded on the optical
disk 100, data after phase encoding modulation is recorded in a
stripe form so as to overlap on pits by irradiating a laser beam in
the form of pluses from a high power laser light source 211 onto,
for example, the reflecting layer 205 of the optical disk 100
through a focusing lens 212 so as to eliminate or remove a part of
the reflecting layer 205. As shown in FIG. 2B, upon reproducing the
signals, the signals, which result from a lowered amount of
reflecting light from the portions where the reflecting layer 205
is eliminated or removed, are intermittently reproduced. The BCA
data is reproduced through the phase encoding demodulation after
the reproduced signals are binarized. The BCA formed by such a
recording system can record a disk identifier which is specific
information for each optical disk 100, and further, the BCA has
such a feature whereby it is impossible to falsify recorded
data.
[0136] FIG. 3 is a diagram which illustrates a recording format of
the BCA 106 shown in FIG. 1. As shown in FIG. 3, a synchronization
code (SY) 301, an error detection code (EDC) 302, an error
correction code 303 and the like are recorded in the BCA 106 so as
to improve the reading-out factor of the BCA data (DATA) 304. By
connecting the plurality of BCA data 304, a disk identification
information 305 is constituted. In the disk identification
information 305, there are recorded types of data that are
recordable into the user data area and the types of data which are
reproducible from the user data area. It is impossible for the data
of BCA 106 to be falisified, and therefore, a user's disk usage can
be limited to a certain degree by means of the disk identification
information that is recorded when the optical disk 100 is
manufactured.
[0137] FIG. 4 shows a sector structure of sector data 401 within
the user data area 102 shown in FIG. 1. Referring to FIG. 4, the
user data area 102 shown in FIG. 1 has a sector structure which is
accessible by a unit of a certain amount, and the sector data 401
is constituted by a header 402, main data 403 and an error
detection code 404.
[0138] The main data 403 is an area in which AV data, computer data
and the like are recorded. A data ID (data identifier) 405, an ID
error detection code 406, scramble control information 407, key
information 408 or the like are recorded in the header 402. A
logical address for identifying sectors or the like is recorded in
the data ID 405, and the ID error detection code 406 is provided
for detecting errors in the data IDs. The scramble control
information 407 is a flag for showing whether or not the main data
has been scrambled, and information corresponding to a key for
descrambling the main data 403 is recorded in the key information
408. As the information corresponding to the key, the descramble
key itself (in the modified preferred embodiment of the modified
preferred embodiment of the first preferred embodiment) or a key
index (in the first preferred embodiment), which is a pointer to
the descramble key which is recorded onto another area of the
optical disk 100, are recorded. An example of FIG. 4 shows the case
where a key index is recorded for referring to the descramble key
recorded in the key management information area 107 shown in FIG. 1
which is another area of the optical disk 100.
[0139] FIG. 5 shows a configuration of the key management
information area 107 shown in FIG. 1. Referring to FIG. 5, the key
management information area 107 is constituted by a key information
area 501, a content information area 502 and a key index list area
503.
[0140] In the key information area 501, the number of recorded key
areas 504 is recorded, and the key information area 501 includes
(a) a descramble key area 505, which is an area for recording the
descramble key to descramble the scrambled AV data or the like, and
(b) a key status area 506 for recording therein a recording status
(indicating unused, area reservation, recorded or the like) of the
descramble key which is recorded in the descramble key area 505. In
the descramble key area 505, plurality of descramble keys are
recorded, and a key index for representing the stored position in
the descramble key area 505 is recorded in the key index list area
503. The above-mentioned plurality of descramble keys are possible
to be referred to by this key index. In the key status area 506,
the status information for representing the recording status of the
descramble keys is stored at a position which is possible to be
referred to by the key index.
[0141] In the content information area 502, the contents which are
recorded on the optical disk 100 are registered when copyright
protection is necessary, and the information with respect to keys
which are used for the contents is registered. The number of
contents 507 registered in the key index list area 503 and content
information 508 for the content number are recorded in the content
information area 502. In addition, a content ID for identifying the
content, the number of descramble keys which are used for the
content, and the pointer to the key index list 509 which records
the used keys are each recorded in the content information 508. The
key index list area 503 is an area for recording indexes to refer
to the keys which are used for the content in a form of in content
unit. A key index for referring to the entire recording area of the
descramble keys which are used for the content is recorded in the
key index list area 503.
[0142] The optical disk of recording type 100 constituted in this
way makes it possible to control the recording operation and the
reproducing operation in accordance with the protection level or
the usage level of the copyright held by the contents. Controlling
the recording and reproducing operations according to the
designated protection or usage level is achieved by recording
information for representing conditions or a status for disk usage
on the disk identification information which is difficult to
rewrite such as a region identifier, a data category identifier and
a disk identifier upon manufacturing, and by detecting such
information by an optical disk and reproducing apparatus. Since
data is recorded in such a manner so as to make it difficult to
rewrite so that a user cannot change the data, even in the case
where the copyright protected content is copied to another optical
disk, the disk identification information cannot be copied while it
remains possible to copy the user data area. Accordingly, by
recording the data as being scrambled by using the disk
identification information on the optical disk, such data on the
optical disk can be
[0143] prevented from being reproduced correctly since there exists
a user data area which cannot be descrambled in an optical disk
having different disk identification information.
[0144] FIG. 15A shows a diagram showing whether or not copying or
reproducing the content is possible in the same region as well as
in a different region in the case where a region identifier is
recorded when the content is recorded in the first preferred
embodiment, and FIG. 15B shows a diagram indicating whether or not
the copying or the reproduction of the content is possible in the
same region as well as in a different region in the case where a
region identifier is recorded in advance when the optical disk is
shipped in the first preferred embodiment.
[0145] For example, as shown in FIG. 15A, in the case where a
region identification code is not recorded when the optical disk is
shipped, and the region identifier, which represents the region
where the contents are available when the contents are recorded, is
recorded in a recording and reproducing area, the usage can be
prevented in another region. However, the contents are recordable
in a disk (for a region RC2 shown in FIG. 15A) to be used in
another region, and it is therefore possible to reproduce the
content correctly. A recording medium in which a digital copying of
the content is possible is provided with a tax imposing system to
protect the benefit of copyright holders which collect an added
charge when the optical disk is sold. However, the added charge
differs according to a particular country and in the case where the
recording medium to be used in another country is utilized
unjustly, the possibility remains that the copyright holders will
not be able to share in the appropriate profit.
[0146] As shown in FIG. 15B, by recording in advance at the time of
shipping in such a way that the region identifier cannot be
falsified, copying or reproduction of the content to an optical
disk to be used in another region can be prevented. In a manner
similar to that as described above, in the case where a data
category identifier is recorded as disk identification information,
copying or reproduction of the content to the disk on which the
data is recordable and reproducible can be limited by comparison
between category identifiers which the record data have. In the
case where an inherent disk identifier for each optical disk is
recorded as disk identification information, the recorded data can
be made available only by the optical disk by encrypting the
recorded data with the disk identifier.
[0147] In the present preferred embodiment, the data which is
scrambled by the disk identification information may be AV data or
computer data which needs copyright protection, or the scrambled
data may be descramble keys for descrambling scrambled AV data or
computer data.
[0148] FIG. 13 is a block diagram showing a method for judging
whether or not a descramble key is a regular descramble key based
on the encrypted descramble key according to the modified preferred
embodiment of the first preferred embodiment. As shown in FIG. 13,
the data which is obtained by adding an error detection code for
detecting errors in the descramble key to the descramble key may be
scrambled by using disk identification information so as to
calculate an encrypted descramble key which may be recorded on the
optical disk. In the optical disk reproducing apparatus, the
encrypted descramble key is decrypted into a descramble key and an
error detection code so as to judge whether or not the decrypted
descramble key is a regular descramble key by detecting errors
based on the parity check in the decrypted error detection code.
For example, in the case of descrambling by using different disk
identification information, an error descramble key is produced so
that an irregular copy can be detected by checking the error
detection code for determining that the decrypted descramble key is
not a regular descramble key.
[0149] As another method for recording disk identification
information, by preparing stampers which are formed with a
plurality of types of disk identification information in the form
of pre-pits and by forming an optical disk from each of the
stampers, different usage limitations may be given to respective
optical disks which are formed from different stampers. In
addition, by scrambling the disk identification information by
using a secret key and by recording the scrambled disk
identification information on the optical disk, the protective
level of the copyright described in the disk identification
information is kept unknown to the users, and as a result, the
copyright protection is further enforced.
[0150] The case where the descramble key itself is recorded as the
information corresponding to the key described in FIG. 4 (in the
modified preferred embodiment of the first preferred embodiment)
and the case where the key index, which is a pointer to the
descramble key which is recorded in another area of the disk, is
recorded (in the first preferred embodiment) will be described with
reference to FIGS. 6A and 6B. FIG. 6A is a block diagram showing a
recording method for recording a descramble key and AV data in the
sector data 401 shown in FIG. 1 according to the modified preferred
embodiment of the first preferred embodiment, and FIG. 6B shows a
block diagram showing a recording method for recording a key index
and AV data to a descramble key in the sector data 401 shown in
FIG. 4 in the user data area 102 shown in FIG. 1 according to the
first preferred embodiment.
[0151] In the case of FIG. 6A, the main data 403 and the descramble
key which is key information 408a which is required for
descrambling of the main data 403 are recorded in the same sector
data 401. Thus, it is necessary to acquire a descramble key which
is required for descrambling when AV data are recorded. That is to
say, the acquisition or the purchase of the key itself is
indispensable or inevitable when AV data are recorded.
[0152] On the other hand, in the case of FIG. 6B, the main data 403
and the key index, which is the key information 408 for referring
to the descramble key area for recording the necessary information
for descrambling the main data 403, are recorded in the same sector
data 401, and the descramble key is recorded in an area which is
designated by the key index. When the AV data are recorded, the key
ID indicating which key among the keys used in the recorded content
can descramble is acquired, and the key information 408 is
acquired. The key information 408 is a key index corresponding to
the key ID from the key index list that is included in the content
information, which is recorded together with the main data 403. The
recording of the descramble key is performed when the descramble
key is obtained to be recorded in the descramble key area that is
shown by the key index corresponding to the key ID. As a result, AV
data and the descramble key corresponding to the AV data can be
recorded independently. That is to say, the recording of AV data
and the acquisition or purchase of the key can be carried out
independently so that the acquisition or the purchase of the key is
not necessarily required when the AV data are recorded. It
therefore becomes possible for the user to utilize a method for
recording the content and acquiring the key when the content is
actually reproduced.
[0153] FIG. 14 shows a configuration view of a descramble area
management table according to a modified preferred embodiment of
the first preferred embodiment. In the above-mentioned preferred
embodiments, in order to correlate the encrypted content with the
descramble key for descrambling its cipher, the cases in which the
key index is recorded for referring the descramble key to the same
sector data 401 are described. However, the descramble area
management table shown in FIG. 14, which manages the corresponding
relationships between the address range of the sectors in which the
encrypted content is recorded and the descramble key, may be used.
This descramble area management table represents the address range
of the sector in which the encrypted content is recorded with the
starting address and the completion address, and when the data of
the sector is reproduced, the descramble key is referred to and
then the encrypted content is descrambled.
[0154] In order to acquire the recorded content and the descramble
key which is used for the recorded content, the content ID that
makes the content identifiable is utilized. As shown in FIG. 5, in
the content information which is recorded in the content management
list within the content information area 502 which is recorded on
the optical disk, the content ID and the list of the descramble key
used for the content are recorded. By having a list configuration
where a plurality of descramble keys can be used for one piece of
content, such services are made available so that a part of the
content or a part of the software can be sold.
[0155] In the modified preferred embodiment described above with
reference to FIG. 13, when the data where the descramble key to
which the error detection code such as a check sum or a cyclic
redundancy check code is added thereto is scrambled by the disk
identification information and is copied unjustly onto another
disk, the descramble key can be detected as an error by being
descrambled with different disk identification information. In such
a case, it is also possible to acquire a descramble key that is
scrambled by disk identification information which is recorded on
the optical disk, and to form a disk which can be reproduced
correctly by replacing that descramble key with the acquired
descramble key.
[0156] The key management information area 107 shown in FIG. 1 is
recorded in a lead-in area 101 which is rewritable. Generally, the
user data area 102 comprises a user area which is accessible from a
drive apparatus of a personal computer, and a spare area for the
defect sector on an optical disk. Moreover, for the conventional
READ command and WRITE command, only the user area can be
accessible as a logical continuous area. By placing the key
management information in the lead-in area 101, direct access from
the drive apparatus of the personal computer or the like can be
prevented so that acquiring a key for descrambling the scrambled AV
data or the like from the personal computer can be made
impossible.
Second Preferred Embodiment
[0157] FIG. 7 shows a block diagram illustrating a configuration of
an optical disk recording and reproducing apparatus of the second
preferred embodiment according to the present invention. This
optical disk recording and reproducing apparatus is provided for
recording contents of AV data such as image data or music data
which require copyright protection for the optical disk 100
according to the first preferred embodiment.
[0158] Referring to FIG. 7, reference numeral 701 denotes an
optical disk of the first preferred embodiment, reference numeral
702 denotes an optical head which is an optical pickup that is
constituted by a semiconductor laser and optical elements, and
reference numeral 703 denotes a recording and reproducing control
circuit for controlling the operation of the semiconductor laser of
the optical pickup 702 and for binarizing the reproduced signals.
Reference numeral 704 denotes a modulating and demodulating circuit
for digitally modulating digital data to be recorded and digitally
demodulating the binarized reproducing signals, and reference
numeral 705 denotes an error detecting and correcting circuit for
error detection and correction processing of errors caused by
scratches, dust or the like on the optical disk 701 and for
performing error correction code generation processing which is
required for the error detection and correction processing.
Reference numeral 706 denotes a buffer memory of a RAM that is used
for a working memory and a data buffer memory of the error
detecting and correcting circuit 705, reference numeral 707 denotes
a descramble circuit for descrambling scrambled recorded AV data,
and reference numeral 708 denotes an MPEG decoding circuit for
expanding compressed recorded dynamic image data or the like.
Reference numeral 709 denotes an output circuit for D/A converting
expanded image data so as to generate and output video signals and
audio signals, reference numeral 710 denotes a control CPU for
controlling the entire operation of the optical disk recording and
reproducing apparatus, and reference numeral 711 denotes a
communication circuit for acquiring a descramble key for
descrambling the cipher placed in the contents. Reference numeral
712 denotes a data receiving circuit for receiving digital data of
the encrypted content such as image data and music data from a
communication terminal apparatus such as a set-top box.
[0159] A data recording operation of the optical disk recording and
reproducing apparatus of FIG. 7 constituted as described above will
now be described. The digital data of the encrypted contents such
as image data or music data that are transmitted from the
communication terminal apparatus such as a set-top box or an MPEG
encoder are temporarily stored in the buffer memory 706 after being
received by the data receiving circuit 712. The error detecting and
correcting circuit 705 generates error detection and correction
code that are required for the error detection and correction
process caused by scratches or dust on the optical disk 701 in the
digital data of the stored contents so as to reconfigure the record
data. For the error detection and correction code, a code such as a
well-known Reed-Solomon code is used. In this case, the
reconstituted record data includes digital data of content and
error detection and correction code. The modulating and
demodulating circuit 704 uses a modulation system such as an 8/16
modulation system upon recording, and digitally modulates the
record data. Also, the recording and reproducing control circuit
703 modulates the intensity of the power of the laser beam that is
outputted from the optical head 702 according to the record data
modulated digitally so that the laser is irradiated onto the
optical disk 701 so as to record the record data-onto the optical
disk 701.
[0160] FIG. 8 shows a flowchart indicating an AV data recording
process that is carried out by the control CPU 710 of the optical
disk recording and reproducing apparatus shown in FIG. 7.
[0161] Referring to FIG. 8, first of all, in step S801, the disk
identification information of the lead-in area 101 is reproduced
prior to recording of the AV data from the optical disk 701. Then,
in step S802 it is determined whether or not the digital data of
the contents to be recorded at the present time are recordable from
the type or class of data that is recordable in the user data area
102 which are recorded in the disk identification information. In
the case of YES in step S802, the recording operation proceeds to
step S803, while in the case of NO, the recording operation is
stopped in step S810, whereupon the recording process of the AV
data is completed.
[0162] In step S803, the data of the sector where the key
management information is recorded in the lead-in area 101 is
reproduced, and in step S804 it is determined whether or not an
area is allocated for the key information that is required for
recording the contents in the reproduced key management
information. In the case of NO in step S804, after allocating an
area for recording the key information in the key management
information area 107, the recording operation proceeds to step
S806. On the other hand, in the case of YES in step S804 the
recording operation proceeds directly to step S806.
[0163] In the case where the content is recorded, the control CPU
710 of the optical disk recording and reproducing apparatus
receives the record data of the encrypted content and information
with respect to the descramble key for descrambling the cipher via
the data receiving circuit 712 from the communication terminal
apparatus. In this case, the information with respect to the key is
the key itself that is used for the contents or a key ID for
indicating to which key the information corresponds from among the
keys that are used in the entire contents. In the case where the
key ID is received, in step S806, the received key ID is converted
into a key index, which is a pointer for indicating an area where a
descramble key corresponding to the key ID is recorded, and the
converted descramble key is placed in a header area of the sector
where the data of the contents to be decrypted with the descramble
key is recorded. Then, in step S807, the control CPU 710 carries
out the following record data processing by controlling the
recording and reproducing control circuit 703, the modulating and
demodulating circuit 704, and the error detecting and correcting
circuit 705. In this record data processing, the codes for the
error detection and correction are added to the sector data which
is desired to be recorded. Then, the sector data with such codes
added thereto are digitally modulated by using a modulation system,
such as a well-known 8/16 modulation system, so that the optical
head 702 is controlled to locate at a predetermined recording
position, and the intensity of the laser beam is modulated
according to the record data that is digitally modulated. By doing
this, the record data is recorded on the optical disk 701, and in
addition, in step S808, it is determined whether or not the
recording of the contents has been completed. In the case of NO,
i.e., recording of the contents has not been completed, the
recording process goes back to step S806 so as to repeat the
above-mentioned processing. In the case of YES in step S808, the
updated key management information is recorded in the key
management information area 107 on the optical disk 701 in step
S809, and then, the recording process of the AV data is
completed.
[0164] FIG. 9 shows a flowchart illustrating an allocating process
of the key management information area that is carried out by the
control CPU 710 of the optical disk recording and reproducing
apparatus shown in FIG. 7. This allocating process is provided for
allocating areas for recording a descramble key prior to recording
data of the content.
[0165] Referring to FIG. 9, in step S901, the information with
respect to the key of the content recorded from an electronic
program guide or the like (including the number of used descramble
keys) is acquired, for example, and then, in step S902, the key
management information within the key management information area
107 that is recorded in the optical disk 701 is reproduced. Then,
in step S903, empty areas of the descramble key area 505 are
searched from the key status area 506 so as to determine whether or
not the descramble key that is used in the content to be recorded
can be recorded. In the case of NO in step S903, the recording
operation is stopped in step S907, and then, the allocating process
is completed. On the other hand, in the case of YES in step S903,
the contents to be recorded are registered in the content list
within the content information area 502 so that recording areas are
allocated by setting area reservation flags in corresponding key
status areas so as to reserve an area that is required for the
recording of a descramble key in the descramble key area 505 in
step S905. In addition, in step S906, a key index indicating
allocated areas for recording descramble keys are formed as a key
list, and then, after a pointer set as the content information is
allocated, the allocation process is completed.
[0166] FIG. 10 shows a flowchart illustrating a recording process
of the descramble key that is carried out by the control CPU 710 of
the optical disk recording and reproducing apparatus shown in FIG.
7. This recording process is provided for recording a descramble
key that is acquired from a key management center in the optical
disk 701.
[0167] Referring to FIG. 10, first of all, in step S1001, after the
disk identification information of the lead-in area 101 on the
optical disk 701 is reproduced, the disk identification information
and the key ID for identifying keys that are required for the
descrambling of the desired content are transmitted to the key
management center via the communication circuit 711 so as to
acquire a descramble key from the key management center in step
S1002. In the key management center, a descramble key that is
required for the descrambling of the content from the given key ID
are selected so that the descramble key is encrypted by using the
information, such as the transmitted disk identification
information, and is then returned.
[0168] After the descramble key corresponding to the key ID is
acquired via the communication circuit 711 from the key management
center in step S1003, the data of the key management information
area 107 is reproduced so that the key index for indicating an area
for recording the descramble key is acquired from the key index
list that is indicated by key ID from among the data within the
reproduced key management information area 107 in step S1004. Then,
in step S1005, the descramble key that is acquired above is
allocated in the descramble key area that is indicated by the key
index, and an acquired flag for indicating a key that is acquired
in the corresponding key status area 506 is set. In addition, in
step S1006, whether or not the acquisition of all the keys are
completed is determined, and then, in the case of NO in step S1006,
the above-mentioned process is repeated by returning to step S1003.
On the other hand, in the case of YES in step S1006, the updated
key management information is recorded in the key management
information area 107 in step S1007, and then, the descramble key
recording process is completed.
[0169] Next, the data reproducing operation of the optical disk
recording and reproducing apparatus of the second embodiment will
be described with reference to FIG. 7. The digital data that is
recorded on the optical disk 701 is reproduced as follows. A laser
beam from the semiconductor laser from the optical head 702 is
irradiated onto the optical disk 701 so that, at that time, the
reflected light which is reflected on the optical disk 701 is
entered into the recording and reproducing control circuit 703 via
the optical head 702. The recording and reproducing control circuit
703 generates and outputs a generated reproduced binarized signal
to the modulating and demodulating circuit 704 by carrying out
amplification and by a binarizing process after photoelectrically
converting the entered reflected light. The modulating and
demodulating circuit 704 digitally demodulates the digitally
modulated signal into a digital signal by using a modulating system
such as a well-known 8/16 modulating system upon recording, and
then, the modulating and demodulating circuit 704 outputs the
resultant digital signal to the error detecting and correcting
circuit 705. Then, the error detecting and correcting circuit 705
uses the buffer memory 706 as a working memory so as to carry out
detecting and correcting processes of the errors that are caused by
scratches or dust on the optical disk 701. This error detecting and
correcting process is carried out by decoding, for example, with a
well-known Reed-Solomon code.
[0170] The reproduced data which are processed for error detection
and correction are outputted to the descramble circuit 707 for
carrying out the descramble process. The descramble circuit 707
uses the descramble key of the key management information area 107
that is reproduced prior to the data reproduction in advance, and
performs a descramble process for the reproduced data, which is
then outputted to the MPEG decoding circuit 708. Then, the MPEG
decoding circuit 708 expands the compressed dynamic image data and
music data, and then, the expanded data is outputted to the output
circuit 709 by the MPEG decoding circuit 708. In addition, the
output circuit 709 D/A converts the inputted expanded data into
video and audio signals, and outputs the resultant video and audio
signals to upper-level apparatuses such as a television set, an
audio device or the like.
[0171] FIG. 11 shows a flowchart illustrating a reproduction
process of AV data that is carried out by the control CPU 710 of
the optical disk recording and reproducing apparatus shown in FIG.
7.
[0172] Referring to FIG. 11, first of all, in step S1101, prior to
the recording of the AV data from the optical disk 701, the disk
identification information within the lead-in area 101 is
reproduced, and in step S1102, it is determined whether or not the
content that is desired to be reproduced at present is reproducible
from the types of reproducible data that are recorded in the disk
identification information. In the case of NO in step S1102, the
reproducing operation is stopped in step S1112, and then, the
reproducing process of the AV data is completed. On the other hand,
in the case of YES in step S1102, the data in the sector where the
key management information is recorded within the key management
information area 107 of the lead-in area 101 are reproduced, and it
is determined whether or not the key information that is required
for the reproduction of the content has been recorded in the key
management information that is reproduced in step S1104. In the
case of YES in step S1104, the reproducing information proceeds to
step S1106 directly. On the other hand, in the case of NO in step
S1104, in step S1105, a descramble key is acquired via the
communication circuit 711 from the key management center which
manages the keys, and the descramble key is recorded in the key
management information area 107 on the optical disk 701. Then, the
reproducing operation proceeds to step S1106.
[0173] Next, in step S1106, the control CPU 710 makes the optical
head 702 move to the user data area of the optical disk 701, and
controls the recording and reproducing control circuit 703, the
modulating and demodulating circuit 704 and the error detecting and
correcting circuit 705 so that the AV data are reproduced. Then, in
step S1107, the descramble key that is required for the
descrambling of the sector data is acquired from the descramble key
area 505 that is indicated by the key index included in the header
of the reproduced sector. Then, in step S1108, the scrambled
information for the descramble key is decoded by descrambling by
means of the disk identification information. In addition, in step
S1108, by checking the error detection code that is added to the
descramble key, it is determined whether or not the descramble key
has an error. In the case of YES in step S1108, the contents are
judged as obtained irregularly (or the contents are copied
irregularly), the reproducing operation is stopped in the step
S1112, and then, the reproducing process of the AV data is
completed.
[0174] On the other hand, in the case of NO in step S1108, the data
of the content is descrambled by the descramble key in S1109, and
the descrambled AV data is outputted to the MPEG decoding circuit
708 in step S1110. Then, the control CPU 710 MPEG-expands the
descrambled AV data through a predetermined MPEG system by
controlling the MPEG decoding circuit 708 and the output circuit
709, and then, the MPEG-expanded AV data is D/A converted into
video signals and audio signals to be outputted to upper-level
devices such as a television set, an audio device or the like.
Then, in step S1111, it is determined whether or not the
reproduction of the content is completed. In the case of NO in step
S1111, the reproducing operation returns to step S1106 so as to
repeat the above-mentioned process. On the other hand, in the case
of YES in step S1111, the reproducing process of the AV data is
completed.
[0175] In the case where an error is detected in step S1109, the
content is regarded as being obtained irregularly, for example, the
content is regarded as being copied irregularly, and the
reproducing operation is stopped. However, the key information may
be acquired from the key management center which manages the keys
via the communication circuit 711 and recorded in the key
management information area 107 on the optical disk 701 by carrying
out the process of step S1105 in the same way as the case where a
key is not recorded. By doing this, even the copied AV data can
become reproducible by obtaining the key in a regular
procedure.
[0176] FIG. 12 shows a flowchart illustrating an acquiring process
of a descramble key that is carried out by the control CPU 710 of
the optical disk recording and reproducing apparatus shown in FIG.
7. This acquiring process is provided for reproducing descramble
keys from the reproduced key index, and this acquiring process is
carried out prior to the reproducing process of the AV data as
shown in FIG. 11.
[0177] Referring to FIG. 12, first of all, in step S1201, it is
determined whether or not the data in the reproduced sector area is
scrambled by the scramble control information. In the case of NO in
step S1201, the acquiring process proceeds to step S1206. On the
other hand, in the case of YES in step S1201, a key index is
acquired by reproducing key information that is recorded in the
same sector area as the above-mentioned sector area in step S1202,
and then, the descramble key that is indicated by the
above-mentioned key index is acquired from the descramble key area
505 in step S1203. Afterwards, in step S1204, the acquired
descramble key is descrambled by using the disk identification
information, and it is determined whether or not an error exists in
the descramble key by checking the error detection code. In the
case of YES in step S1204, the reproducing operation is stopped in
step S1205, and the acquiring process of the descramble key is
completed. On the other hand, in the case of NO in step S1204, the
reproducing operation proceeds to step S1206. When the reproduced
sector is not scrambled or when an error is not found to exist as a
result of descrambling the descramble key by the disk
identification information, permission for the reproducing
operation is granted in step S1206, the data of the reproduced
sector is outputted, and then, the acquiring process of the
descramble key is completed.
[0178] As described above, in the optical disk and in the optical
disk recording and reproducing apparatus of the preferred
embodiments according to the present invention, the recording and
reproducing operations can be controlled by the user by using disk
identification information for read-only that are made at a disk
manufacturing stage. In addition, by scrambling a part of the data
by using the above-mentioned disk identification information,
normally reproducing data on the disk where the user data area is
physically copied can be prevented. Also, by allocating the
descramble key that is required for the data descrambling in a
different area from the area for the data, the recording of the
content and the recording of the descramble key can be carried out
independently. Thus, by recording the contents and by acquiring the
descramble key if necessary, for example, when the data of the
content are reproduced, the content can be maintained in a
reproducible state or status. At this time, by scrambling the
descramble key with the disk identification information, an
irregular usage through physical copying can be explicitly
prevented in the same way as that described above. In addition to
this, a disk that is copied irregularly could become an optical
disk which can be reproduced normally by formally acquiring the
descramble key that is scrambled with the disk identification
information of the optical disk from the key management center and
by recording the acquired descramble key in the optical disk.
[0179] Although already encrypted data of the content that is
inputted to the optical disk recording and reproducing apparatus
are described above, by providing a circuit for encrypting the
content within the optical disk recording and reproducing
apparatus, the same effects can be obtained by encrypting the data
of the inputted contents and by recording that data on the optical
disk.
[0180] Although in the second preferred embodiment, by encrypting
only the descramble key which is required for decrypting the
encrypted content by using the disk identification information,
copying between the disks having different disk identification
information is prevented, copying can be prevented by encrypting
the content itself by using the disk identification information. In
addition, by encrypting the disk identification information by
using a secret key, it becomes possible to make the irregular
decrypting of the content that is recorded on the disk more
difficult.
Advantageous Effects of First and Second Preferred Embodiments
[0181] An optical disk of the first and second preferred
embodiments according to the present invention records the disk
identification information by carrying out the recording operation
and the reproducing operation into the user data area for each
optical disk in a read-only area which is not rewritable.
Therefore, the optical disk of the first and second preferred
embodiments can control the recording operation and the reproducing
operation of the contents onto the optical disk by the user by
using the information that is recorded upon manufacturing the
optical disk.
[0182] An optical disk of the preferred embodiments according to
the present invention can prevent the disk identification
information from being copied so as to make the correct decoding
and reproduction of the data impossible even in the case where the
user data area information is copied by the user onto a different
recording-type of optical disk by recording, the encrypted data in
the user data area of the optical disk with a key of the disk
identification information of read-only which is impossible to be
rewritten.
[0183] An optical disk of the first and second preferred
embodiments according to the present invention makes it possible to
carry out independently (a) an acquisition of the data which needs
copyright protection such as movies and music, and (b) an
acquisition of the descramble key for decrypting the encryption by
recording the encrypted data and the descramble key for decrypting
the encryption in different sector areas. In addition, by
encrypting and recording the descramble key with a key of the disk
identification information, even in the case where the user data
area information is copied onto another recording-type optical disk
by the user, the disk identification information cannot be copied,
and a correct decoding and reproduction of the data becomes
impossible. Further, by acquiring and recording the encrypted
descramble key with a key of the disk identification information on
the optical disk where it is copied, a correct decoding and
reproduction of the data can be made possible.
Third Preferred Embodiment
[0184] Next, an encrypted content recording and reproducing method
of a third preferred embodiment according to the present invention
will be described with reference to the drawings. FIG. 16 shows a
plan view illustrating a data recording area of an optical disk
1101 of the third preferred embodiment according to the present
invention.
[0185] Referring to FIG. 16, reference numeral 1101 denotes a
recording medium which can record digital data, and which is a
recording-type optical disk such as a rewritable or non-rewritable
optical disk, reference numeral 1102 denotes a control user data
area in which disk information is recorded in a form of minute
concavo-convex pits, and reference numeral 1103 denotes a user data
area in which the user records data by irradiating a light beam of
a laser onto the optical disk. Reference numeral 1104 denotes an
BCA in which disk ID is recorded. In the BCA 1104, a recording film
on minute concavo-convex pits in an inner periphery section of the
control user data area 1102 is trimmed by partially irradiating a
laser beam of a pulse laser such as a YAG laser or the like onto
the recording film so that a plurality of trimming areas 1105 are
formed in an elongated shape in the radius direction to thereby
record a disk ID which is the descrambled identification
information.
[0186] FIG. 17 is a waveform diagram showing a signal waveform of a
reproduced signal 1201 and a reproduced binarized signal 1207 in a
BCA reproducing circuit 1401 according to the third preferred
embodiment. FIG. 18 shows a block diagram illustrating a
configuration of the BCA reproducing circuit 1401 according to the
third preferred embodiment. FIG. 17 shows a reproducing signal 1201
when data of the BCA 1104 is reproduced In FIG. 18, reference
numeral 1301 denotes an optical pickup, reference numeral 1302
denotes a pre-amplifier, reference numeral 1303 denotes a low-pass
filter (LPF), reference numeral 1304 denotes a binarizing circuit,
and reference numeral 1305 denotes a demodulation circuit.
[0187] Referring to FIG. 18, a laser beam that is outputted from
the optical pickup 1301 irradiates the BCA 1104 of the optical disk
1101, and the reflected light is photoelectrically converted by the
optical pickup 1301. Thereafter, an electric signal which has been
photoelectrically converted is amplified by the pre-amplifier 1302
so as to obtain a reproduced signal 1201. In this case, the
reproduced signal 1201 shown in FIG. 17 has a level corresponding
to the concavo-convex pits of the control user data area 1102, and
in this reproduced signal 1201, each of reference numerals 1202,
1203 and 1204 denotes a trimming portion where signals in a form of
concavo-convex pits drop out when the recording film is removed by
the trimming process by the pulse laser. This trimming process is
carried out by the manufacturer of the optical disk.
[0188] Referring back to FIG. 18 for a description of the BCA
reproducing circuit 1401, the reproduced signal 1201 is inputted to
the low-pass filter 1303, which then removes the modulated signal
that is formed by the concavo-convex pits. Thereafter, the low-pass
filter 1303 outputs a resultant signal to the binarizing circuit
1304. The reproduced signal that is inputted into the binarizing
circuit 1304 is binarized by using a slice level 1206 which is a
level that is significantly lower than the slice level 1205,
instead of the normal slice level 1205 which binarizes a signal of
control user data area 1102 so as to obtain the reproduced
binarized signal 1207. The reproduced binarized signal 1207 that is
outputted from the binarizing circuit 1304 is demodulated by a
demodulation circuit 1305 so as to obtain the disk ID signal
1306.
[0189] As described above, by adding the disk identification
information for identifying an optical disk, management of the
optical disk can be easily implemented. Also, by recording the BCA
1104 in a form of concavo-convex pits, the information for
identifying the optical disks within the BCA 1104 can be prevented
from being easily falsified. In addition, since the control user
data area 1102 and the BCA 1104 shown in FIG. 16 are adjacent to
one another, the data of the BCA 1104 can be continuously
reproduced when the data of the control user data area 102 are
reproduced, or the data of the control user data area 102 can be
continuously reproduced when the data of the BCA 1104 are
reproduced. Therefore, it becomes possible to accelerate the
process for obtaining the information of the BCA 1104 for
identifying optical disks quickly by the CPU when, for example, the
optical disk is started up, and for recording the encrypted
content.
[0190] Although the BCA 1104 of the third preferred embodiment is
formed so as to trim the recording film in a form of concavo-convex
pits in the inner periphery section of the control user data area
1102, the recording film, which constitutes an optical disk of
recording type that is either a rewritable or non-rewritable
optical disk, is easily affected by heat as compared with the
reflecting film that is formed on a read-only optical disk. By
trimming the inner periphery section of the control user data area
1102, the user data area 1103 can be protected from the heat that
is emitted upon trimming as compared with the case where the outer
periphery section is trimmed. Also, the reason why the BCA 1104 is
formed on the inner peripheral side of the control user data area
1102 is that a margin should be taken into consideration in the
case where the diameter of the spot of a laser beam changes due to
the instability of a focusing servo circuit of the laser
device.
[0191] The data that are recorded in the BCA 1104 before trimming
may be recorded in the control user data area 1102. The data that
are recorded in the BCA 1104 are also recorded in the control user
data area 1102, and this leads to the above-described data of the
control user data area 1102 being protected from the trimming. In
addition, when the data that are recorded in the BCA 1104 are
recorded continuously and repetitively from the BCA 1104 to the
control user data area 1102, the position of the BCA 1104 can be
predicted by finding the above-described data of the control user
data area 1102.
[0192] Next, the procedure for recording the encrypted content by
the disk ID through a network on an optical disk 1101 having the
above-mentioned BCA 1104 will be described. In the third to fifth
preferred embodiments, a network means, for example, the Internet,
the public telephone line or other communication lines such as
leased lines or circuits. FIG. 19 shows a block diagram
illustrating a configuration of an optical disk recording and
reproducing system according to the third preferred embodiment, and
illustrates an apparatus configuration for recording encrypted
contents on an optical disk of recording type 1101, which is either
a rewritable or non-rewritable optical disk having the
above-mentioned BCA 1104.
[0193] Referring to FIG. 19, an optical disk recording and
reproducing system is constituted by comprising an optical disk
recording and reproducing apparatus 1410 and an encryption section
1406 that are connected to each other through a network 1405 such
as the Internet. The optical disk recording and reproducing
apparatus 1410 comprises an optical pickup 1301, a BCA reproducing
circuit 1401, the Internet (interface) 403, a recording circuit
1411, a data reproducing section 1412, and an encryption decoder
1413. Also, the encryption section 1406 comprises an interface
1404, a content memory 1407, and an encryption encoder 1408.
[0194] First of all, a laser beam that is outputted from the
optical pickup 1301 irradiates, for example, the BCA 1104 of the
RAM type optical disk 1101, and then, after the reflected light is
photoelectrically converted by the optical pickup 1301, a
reproduced signal which has been photoelectrically converted is
inputted to the BCA reproducing circuit 1401. The BCA reproducing
circuit 1401 reproduces a disk ID signal 1402 within the BCA based
on the inputted reproduced signal, outputs the reproduced disk ID
signal 1402 to the encryption decoder 1413, and also simultaneously
outputs the same disk ID signal 1402 to the encryption encoder 1408
of the encryption section 1406 via the interface 1403 and 1404 as
well as the network 1405. The encryption encoder 1408 encrypts data
of the content or scrambles data of the content for image and
speech sound so that the disk ID signal 1402 becomes a decipher key
for decrypting the encryption on the optical disk 1101 where the
data of the content within the content memory 1407 is recorded.
[0195] In the third preferred embodiment, a process of encrypting
the content 1407 by using the disk ID signal 1402 as a cipher key
means the same as the encrypting process. Also, in the third
preferred embodiment, encrypting and decrypting are considered as a
relationship between a lock and a key so that closing the lock with
the key is referred to as encrypting and opening the lock with the
key is referred to as decrypting. Accordingly, encrypting and
decrypting differ in actual operation from each other; however, the
keys for encrypting and for decrypting are the same as each other.
The content 1407 is denoted by C, the disk ID signal 1402 is
denoted by BCAS, the encrypted content 1409 is denoted by C[BCAS],
and the operation for the encrypting process is denoted by *.
Accordingly, the following equation can be represented:
C*BCAS=C[BCAS) (1).
[0196] The content 1409 that is encrypted by the encryption section
1406 is sent to a recording circuit 1411 of the recording and
reproducing apparatus 1410 via the interface 1403 and 1404 as well
as the network 1405. The recording circuit 1411 digitally modulates
the data of the inputted content in a predetermined manner, and
records the data of the content onto the optical disk 1101 by
modulating the intensity of the laser beam from the optical pickup
1301 corresponding to the digitally modulated data and irradiating
the laser beam onto the optical disk 1101.
[0197] Next, when the above-described content that is encrypted and
recorded on the optical disk 1101 is reproduced, a laser beam that
is outputted from the optical pickup 1301 irradiates the area where
the above-described encrypted content of the user data area 1103 is
recorded, and, after the reflected light is photoelectrically
converted by the optical pickup 1301, the reproduced signal which
has been photoelectrically converted is inputted to the data
reproducing section 1412. The data reproducing section 1412 A/D
converts the inputted reproduced signal into digital data, and
outputs the digital data to the encryption decoder 1413. On the
other hand, a laser beam from the optical pickup 1301 is irradiated
onto the BCA 1104 of the optical disk 1101, and, after the
reflected light is photoelectrically converted by the optical
pickup 1301, the reproduced signal which has been photoelectrically
converted is inputted to the BCA reproducing circuit 1401. The BCA
reproducing circuit 1401 A/D converts the inputted reproducing
signal so as to generate the disk ID signal 1402, and then, the
disk ID signal 1402 is outputted to the encryption decoder
1413.
[0198] The encryption decoder 1413 uses the inputted disk ID signal
1402 as a key for decrypting the data of the encrypted content. At
this time, when the content is regularly recorded on the optical
disk 1101, the key for decrypting the encrypted content that is
recorded on the optical disk 1101 is the disk ID signal 1402 of the
optical disk 1101, and the disk ID signal 1402 that is outputted
from the BCA reproducing circuit 1401 upon reproduction is also the
disk ID signal (BCAS) of the optical disk 1101. Accordingly, the
content which is either decrypted or descrambled is outputted from
the encryption decoder 1413 as an output signal 1414. When the
operation for the decoding process is denoted by #, the following
equation can be represented:
C[BCAS] # BCAS=C (2).
[0199] In this case, when the data of the content is image data,
the image data such as an MPEG signal is expanded so as to obtain
data of an image signal.
[0200] As described above, the encrypting of the third preferred
embodiment has a disk ID as a key, and since only one disk ID
exists corresponding to one optical disk, there is an advantageous
effect such that the same encrypted content can be recorded only on
that optical disk. That is to say, when the above-described content
1407 is attempted to be copied and reproduced onto another optical
disk which has another disk ID of ID2 from a regular optical disk
which has, for example, a disk ID of ID1, ID2 is outputted as the
disk ID signal 1402 from the BCA reproducing circuit 401. However,
the encrypted content is encrypted with a disk ID signal of ID1,
and therefore, the encrypted content cannot be decoded by the
encryption decoder 1413.
[0201] The encrypting encoder 1408 is not located at a supplying
source of the content, and is located on the side of the recording
and reproducing apparatus in the network, then it may be formed in
a form of an IC card or the like on which the encrypting encoder
1408 is mounted. Also, since the above-mentioned optical disk 1101
is encrypted by using only the disk ID, data can be reproduced with
an arbitrary optical disk recording and reproducing apparatus
having the BCA reproducing circuit 1401 and the encryption decoder
1413.
Fourth Preferred Embodiment
[0202] Next, an encrypted content recording method of the fourth
preferred embodiment according to the present invention will be
described with reference to the drawings. FIG. 20 is a block
diagram illustrating a configuration of an optical disk recording
and reproducing system of a fourth preferred embodiment according
to the present invention, which shows an apparatus configuration
for recording encrypted content on a recording-type optical disk
which is either a rewritable or non-rewritable optical disk having
a BCA. In the following description of the fourth preferred
embodiment, a description of the same elements that were described
with respect to the third preferred embodiment are omitted.
[0203] Referring to FIG. 20, the optical disk recording and
reproducing system according to the fourth preferred embodiment
comprises a CATV company apparatus 1501, a key issuing center
apparatus 1507, a CATV decoder 1506, an optical disk recording and
reproducing apparatus 1514, and a television set 1530. In this
case, the CATV company apparatus 1501 comprises a content memory
1502 for storing data of contents such as movie software, a first
cipher key memory 1503 for storing a first cipher key, and a first
cipher encoder 1504. Also, the key issuing center apparatus 1507
comprises a control section 1507a for controlling the operation of
the key issuing center apparatus 1507, a time limiting information
memory 1510 for storing time limiting information, and a recording
admission code memory 1511 for storing a limiting admission code.
In addition, the CATV decoder 1506 comprises a system ID memory
1508 for storing a system ID of the CATV decoder 1506, a first
cipher decoder 1513, a second cipher encoder 1516, and a company
identification signal memory 1523 that is provided within an IC
card 1522. Furthermore, the optical disk recording and reproducing
apparatus 1514 comprises a recording circuit 1518, a data
reproducing section 1519, a BCA reproducing circuit 1521, a second
cipher decoder 1520, and a company identification signal memory
1526 that is provided within an IC card 1524.
[0204] First of all, the first cipher encoder 1504 of the CATV
company apparatus 1501 encrypts the data of the content, such as
movie software, that is stored in the content memory 1502 by using
a first cipher key that is stored in the first cipher key memory
1503 so as to generate a first encrypted content 1505. Then, the
generated first encrypted content 1505 is transmitted to the first
cipher decoder 1513 of the CATV decoder 1506 for each user via the
network. When the data that is stored in the content memory 1502 of
the CATV company apparatus 1501 is denoted by C, the first cipher
key stored in the first cipher key memory 1503 is denoted by FK,
and the first encrypted content 1505 is denoted by C[FK]. Then, the
following equation can be represented:
C*FK=C[FK] (3).
[0205] The CATV decoder 1506 transmits, via the network to the key
issuing center apparatus 1507,
[0206] (a) a system ID for the CATV decoder 1506 that is stored in
the system ID memory 1508; and
[0207] (b) a title code 1509 that is inputted by using, for
example, a keyboard (not shown) of the CATV decoder 1506, which is
added in advance to the above-mentioned content that is desired to
be recorded on the audio-type or RAM-type optical disk 1101. In
this case, the title code 1509 may be inputted by being selected
according to the TV screen of the television set 1530, the title
code 1509 may be inputted directly using the keyboard or may be
inputted from a remote controller or the like. Accordingly, the
title code 1509 may be obtained by a user's acquisition in his own
way, or the title code 1509 may be transmitted to the CATV decoder
1506 together with the first encrypted content 1505. The title code
1509 may be sent in advance at a different time than the
transmission time of the first encrypted content 1505 in a form
such as a program guide.
[0208] Based on the system ID of the CATV decoder 1506 and the
title code 1509 of the above-mentioned content, the control section
1507a of the key issuing center apparatus 1507 refers to the time
limiting information that is stored in the time limiting
information memory 1510 and the recording admission code that is
stored in the recording admission code memory 1511, and transmits a
key (K) 1512 corresponding to these data of the recording admission
code and the time limiting code, together with the recording
admission code and the time limiting code, via the network to the
first cipher decoder 1513 of the CATV decoder 1506. The time
limiting information allows the same content to be distinguished
from among the cases where the same content is broadcasted a
plurality of times at different times. When the first decipher key
is denoted by FK, the system ID of the CATV decoder 1506 is denoted
by DID, the time limitation information is denoted by TIME, the
recording admission code is denoted by COPY, and the title code
1509 of the content is denoted by T. Then, the key (K) satisfies
the relationship that is indicated by the following equation:
FK=K*T*DID*TIME*COPY (4).
[0209] It is determined whether the recording admission code that
is stored in the record permission (admission) code memory 1511 is
permitted only for watching and listening, or for both of watching
and listening, and recording, based on a judgment result when the
CATV company apparatus 1501, for example, judges whether or not the
broadcast content is a new work or an old work.
[0210] The first cipher decoder 1513 of the CATV decoder 1506
decrypts the first encrypted content 1505 when the first decipher
key (FK), the key (K) 1512, the title code 1509 of the
above-mentioned content, the system ID, the record permission code
and the time limitation information satisfy the abovementioned
relationship, and the present time information outputted from the
clock circuit 1527 satisfies the condition of the time limitation
information. In this case, when the above-mentioned encrypted
content are an image signal, the descrambled image signal is
outputted from the first cipher decoder 1513 to the television set
1530, and then, the user can watch an image of the image signal and
listen to an audio signal corresponding to the image signal. In
this case, the decrypting process of the first cipher decoder 1513
is expressed by the following equation: 1 C [ FK ] # ( K * T * DID
* TIME * COPY ) = C [ FK ] # FK = C . ( 5 )
[0211] When the record permission code permits only watching and
listening, the content data can be recorded on the optical disk
1101. However, when both of watching and listening, and recording
are permitted, the content data can be recorded on the optical disk
1101. Therefore, this method will be described as follows.
[0212] The BCA reproducing circuit 1521 of the optical disk
recording and reproducing apparatus 1514 reproduces the data of the
BCA 1104 of the optical disk 1101 so as to obtain the disk ID
signal 1515, and outputs the disk ID signal to the second cipher
encoder 1516 of the CATV decoder 1506. The second cipher encoder
1516 of the CATV decoder 1506 encrypts the data of the content
outputted from the first cipher decoder 1513 by using the disk ID
signal 1515 as the second cipher key so as to generate a second
encrypted content 1517, and outputs the generated second encrypted
content 1517 to the recording circuit 1518 of the optical disk
recording and reproducing apparatus 1514. It is to be noted that
the above-mentioned encrypting of the second cipher decoder 1516 is
limited to the time when the first encrypted content is decrypted
and outputted from the first cipher decoder 1513. The content which
is the output signal from the first cipher decoder 1513 is denoted
by C, the disk ID signal 1515 which is the second cipher key is
denoted by BCAS, and the second encrypted content 1517 is denoted
by C[BCAS ]. Then, the following equation can be represented:
C*BCAS=C[BCAS] (6).
[0213] The second encrypted content 1517 that is outputted to the
recording circuit 1518 of the optical disk recording and
reproducing apparatus 1514 is modulated by using, for example, a
well-known 8/16 modulation system to the recording circuit 1518,
and then, the modulated signal is recorded in the user data area
1103 on the optical disk 1101 by the optical pickup (not shown).
When the above-mentioned content that is encrypted and recorded on
the optical disk 1101 is reproduced, the laser beam that is
outputted from the optical pickup is irradiated onto an area where
the above-mentioned encrypted content is recorded on the optical
disk 1101 so that the reflected light enters the optical pickup.
The above-mentioned optical pickup photoelectrically converts the
entered reflected light into a reproduced electric signal, and
then, the reproduced signal which has been photoelectrically
converted is outputted to the data reproducing section 1519. The
data reproducing section 1519 A/D converts the inputted reproduced
signal into a digital reproduced signal, and then, the digital
reproduced signal is outputted to the second cipher decoder
1520.
[0214] On the other hand, a laser beam that is outputted from the
optical pickup is irradiated onto the BCA 1104 of the optical disk
1101 so that the reflected light enters the optical pickup.
[0215] The above-mentioned optical pickup photoelectrically
converts the inputted reflected light into a reproduced electric
signal, and then, the reproduced signal which has been
photoelectrically converted is outputted to the BCA reproducing
circuit 1521. The BCA reproducing circuit 1521 generates the disk
ID signal 1515 based on the inputted reproduced signal, and the
generated disk ID signal is outputted to the second cipher decoder
1520. In response to the disk ID signal 1515, the second cipher
decoder 1520 decrypts the reproduced encrypted content outputted
from the data reproducing section 1519 by using the inputted disk
ID signal 1515 as a key. At that time, in the case where the
content is regularly recorded on the optical disk 1101, the key for
decrypting the encrypted content that is recorded on the optical
disk 1101 is the disk ID of the optical disk 1101, and the disk ID
signal 1515 that is outputted from the BCA reproducing circuit 1521
is also the disk ID signal (BOAS) of the optical disk 1101.
Therefore, the second cipher decoder 1520 can normally carry out
the decrypting process. Accordingly, the data of the content that
are decrypted or descrambled are outputted from the second cipher
decoder 1520 as an output signal 1525. In this case, the decrypting
process of the second cipher decoder 1520 can be expressed in the
following equation. When the data content is an image signal, the
second cipher decoder 1520 expands, for example, an MPEG signal to
reproduce an original image signal, and then, outputs the image
signal.
C[BCAS] # BCAS=C (7)
[0216] The above-mentioned optical disk 1101 is encrypted by using
only the disk ID signal (BCAS) 1515, and therefore, it is possible
to reproduce content data by an arbitrary optical disk recording
and reproducing apparatus comprising a BCA reproducing circuit 1521
and the second cipher decoder 1520. Although the encryption
encoders 1504 and 1516 perform encryption and the encryption
decoders 1513 and 1520 perform decryption in the above description,
encrypting and decrypting may be performed by a configuration such
that programs for encryption algorithms and decryption algorithms
are included in the program that is carried out by the CPU which is
the control section within each of the apparatuses 1501, 1506 and
1514.
[0217] Although, in the fourth preferred embodiment, the second
cipher encoder 1516 of the CATV decoder 1506 encrypts the content
by using the disk ID signal 1515 as the second cipher key, the
content may be encrypted as follows. For example, the IC card 1522
prepared for each CATV company apparatus 1501 may be mounted on the
CATV decoder 1506, and the company identification signal that is
recorded within the company identification signal memory 1523 of
the IC card 1522 and the disk ID signal (BCAS) that is reproduced
by the BCA reproducing circuit 1521 may be combined to be used as
the second cipher key for encrypting the content by the second
cipher encoder 1516. The content of the output signal from the
first cipher decoder 1513 is denoted by C, the disk ID signal 1515
which is the first second cipher key is denoted by BCAS, the
company identification signal 1523 which is the second cipher key
is denoted by CK, and the second encrypted content 1517 is denoted
by C[BCAS, CK]. Then, the encrypting process of the second cipher
encoder 1516 is expressed by the following equation:
C*BCAS*CK=C[BCAS, CK] (8).
[0218] Next, when the content that is encrypted and recorded on the
optical disk 1101 is reproduced, a laser beam that is outputted
from the optical pickup is irradiated onto an area in which the
above-described encrypted content has been recorded on the optical
disk 1101 so that the reflected light enters the optical pickup.
The optical pickup photoelectrically converts the entered reflected
light to a reproduced signal, which is then outputted to the data
reproducing section 1519. The data reproducing section 1519 A/D
coverts the inputted reproduced signal into a digital reproduced
signal, which is then outputted to the second cipher decoder 1520.
On the other hand, a laser beam that is outputted from the optical
pickup is irradiated onto the BCA 1104 of the optical disk 1101 so
that the reflected light enters the optical pickup. The optical
pickup photoelectrically converts the entered reflected light into
a reproduced signal, which is outputted to the BCA reproducing
circuit 1521. The BCA reproducing circuit 1521 reproduces the disk
ID signal 1515 based on the inputted reproduced signal, and then,
the disk ID signal 1515 is outputted to the second cipher encoder
1516 and the second cipher decoder 1520.
[0219] In addition, the company identification signal that is
stored in the company identification signal memory 1526 of the IC
card 1524 mounted on the optical disk recording and reproducing
apparatus 1514 is inputted to the second cipher decoder 1520. The
company identification signal may not be recorded within the
company identification signal memory 1526 of the IC card 1524, for
example, upon installation of a recording program of the optical
disk recording and reproducing apparatus 1514, but instead, the
company identification signal may be recorded in a memory (not
shown) that is connected to a CPU of a control section of the
optical disk recording and reproducing apparatus 1514.
Alternatively, the company identification signal may be inputted by
using a keyboard (not shown) of the optical disk recording and
reproducing apparatus 1514.
[0220] The second cipher decoder 1520 decrypts the encrypted
content by using the inputted disk ID signal 1515 and the company
identification signal as decipher keys. At this time, in the case
where the user of the CATV decoder 1506 contracts formally with a
particular CATV company having the CATV company apparatus 1502, and
the content 1502 is regularly recorded on the optical disk 1101,
the first decipher key for the encrypted content that are encrypted
and recorded on the optical disk 1101 is just the disk ID signal
(BCAS) of the optical disk 1101 which will be reproduced exactly at
that moment, and the second cipher key is the company
identification signal (CK) that is stored in the company
identification signal memory 1526 of the IC card 1524 supplied from
the contracted CATV company. Accordingly, the outputted signal 1525
of the decoded or descrambled contents is outputted from the second
cipher decoder 1520. In this case, the decrypting process of the
second cipher decoder 1520 is expressed in the following equation.
When the content is an image signal, for example, an MPEG signal is
extended by the second cipher decoder 1520, and then, an output
signal 1525 of the image signal is outputted.
C[BCAS, CK] # (BCAS*CK)=C (9)
[0221] Since the content of the above-described optical disk 1101
is encrypted by using the disk ID signal 1515 and the company
identification signal, it is possible to carry out reproduction by
an arbitrary optical disk recording and reproducing apparatus
comprising the BCA reproducing circuit 1521 and the second cipher
decoder 1520 if the contract is made with the CATV company which
supplies the above-mentioned content. On the contrary, if the
contract is not made with above-mentioned CATV company, the company
identification signal cannot be obtained, and the content therefore
cannot be reproduced, which thereby makes it possible to
distinguish the contracted user from non-contracted user.
[0222] Also, since in the fourth preferred embodiment each user
sends a disk ID signal from the optical disk recording and
reproducing apparatus 1514 to the CATV decoder 1506 that is located
at his or her own home to encrypt image data or the like, it is not
necessary for the CATV apparatus 1501 to change encrypted content
that is individually delivered to each user. Therefore, the system
for broadcasting can be simplified to supply the same content to a
mass audience at a low cost. In addition, according to the fourth
preferred embodiment, recording on only one RAM-type optical disk
can be permitted for each user having the CATV decoder 1506.
[0223] Although the case where the content is broadcasted from a
head end of the cable television system is described in the fourth
preferred embodiment, the present invention is not limited thereto,
and the present invention can be applied to broadcasting by using a
radio wave.
Fifth Preferred Embodiment
[0224] A method for recording and reproducing encrypted content of
a fifth preferred embodiment according to the present invention
will be described with reference to the drawings. FIG. 21 shows a
plan view illustrating a data recording area of an optical disk
1601 of the fifth preferred embodiment according to the present
invention, and FIG. 22 is a block diagram showing a configuration
of an optical disk recording and reproducing system according to
the fifth preferred embodiment. In the fifth preferred embodiment,
the description of the elements which are common with the third and
the fourth preferred embodiments are omitted in the following
description.
[0225] Referring to FIG. 21, reference numeral 1601 denotes a
recording-type optical disk which is either a rewritable type or
non-rewritable type of optical disk, reference numeral 1602 denotes
a control user data area in which disk information is recorded in a
form of concavo-convex pits, reference numeral 1603 denotes a user
data area into which the user records the data (recording data) by
irradiating a light beam from a laser onto the optical disk, and
reference numeral 1604 denotes an BCA in which a disk ID is
recorded.
[0226] In the BCA 1604, a plurality of trimming areas 1606 having
an elongated shape in the radius direction are formed by partially
trimming a recording film on concavo-convex pits in the inner
peripheral section of the control user data area 1602 by using a
pulse laser such a YAG laser or the like. The trimming is carried
out by the disk manufacturer. Also, by adding the disk ID to the
data recorded in the BCA 1604, the management of the optical disk
can be easily implemented. In addition, by recording the data of
the BCA 1604 on the concavo-convex pits, the information for
identifying the optical disk which is recorded in the BCA 1604 can
be prevented from easily being falsified.
[0227] In addition, by arranging the control user data area 1602
and the BCA 1604 so as to be adjacent to each other, the data of
the BCA 1604 can be reproduced continuously when the data of the
control user data area 1602 are reproduced, or the data of the
control user data area 1602 can be reproduced continuously when the
data of the BCA 1604 are reproduced. Therefore, it becomes possible
to accelerate the process for obtaining or acquiring information of
the BCA 1604 so as to identify the optical disk quickly by the CPU,
for example, when the optical is disk is started up and for
recording the encrypted contents.
[0228] Although the BCA 1604 of the fifth preferred embodiment is
formed by trimming the recording film on the concavo-convex pits in
the inner periphery section of the control user data area 1602, the
recording film which constitutes an optical disk of recording type
that is either a rewritable type or non-rewritable-type of optical
disk is easily affected by heat, as compared with the reflecting
film which is formed on a read-only optical disk. By trimming the
inner periphery section of the control user data area 1602, the
recording data of the user data area 1603 can be protected from
heat that is generated upon trimming as compared with that when the
outer periphery section is trimmed. The reason why the BCA 1604 is
formed on the inner peripheral side of the control user data area
1602 is that a margin is taken into consideration when the diameter
of the beam spot from a laser beam fluctuates due to instability of
a focusing servo circuit of a laser device. The data recorded in
the BCA 1604 before trimming maybe recorded in the control user
data area 1602. The data recorded in the BCA 1604 can be recorded
in the control user data area 1602 so that the above-mentioned data
of the control user data area 1602 can be protected upon
trimming.
[0229] In addition, when the above-mentioned data is recorded
continuously and repetitively from the BCA 1604 to the control user
data area 1602, the position of the BCA 1604 can be predicted by
finding out the above-mentioned data in the control user data area
1602. Also, the data in the key information recording area 1605 is
recorded by irradiating a light beam in the same way as that of the
user data area 1603.
[0230] In a manner similar to that of the fifth preferred
embodiment, by arranging the control user data area 1602 and the
key information recording area 1605 so as to be adjacent to each
other, the data in the key information recording area 1605 can be
reproduced continuously when the data of the control user data area
1602 are reproduced or the data of the control user data area 1602
can be reproduced, continuously when the data of the key
information recording area 1605 are reproduced. Therefore, it
becomes possible to accelerate the process for obtaining the
information of the BCA 1604 to identify the optical disk quickly by
a CPU when, for example, the optical disk is started up and for
reproducing the encrypted content.
[0231] Referring to FIG. 22, the optical disk recording and
reproducing system according to the fifth preferred embodiment
comprises a CATV company apparatus 1701, a key issuing center
apparatus 1707, a CATV decoder 1706, an optical disk recording and
reproducing apparatus 1714, and a television set 1730. In this
case, the CATV company apparatus 1701 comprises a content memory
1702 for storing the content such as movie software, a first cipher
key memory 1703 for storing a first cipher key, and a first cipher
encoder 1704. Also, the CATV decoder 1706 comprises a system ID
memory 1708, a first cipher decoder 1713, and a clock circuit 1725
for outputting the present time information. Further, the key
issuing center apparatus 1707 comprises a control section 1707a for
controlling the operation of the key issuing apparatus 1707 and a
time limiting information memory 1710. Further, the optical disk
recording and reproducing apparatus 1714 comprises a recording
circuit 1717, a key information recording circuit 1719, a BCA
reproducing circuit 1720, a data reproducing section 1721, a second
cipher decoder 1722 and a key information reproducing section
1723.
[0232] First of all, the first cipher encoder 1704 of the CATV
company apparatus 1701 encrypts data of the content such as movie
software which is stored in the content memory 1702 by using the
first cipher key 1703 so as to generate a first encrypted content
1705, and the first cipher encoder 1704 transmits the generated
first encrypted content 1705 to the first cipher decoder 1713 of
the CATV decoder 1706 of each user through the network. The content
that is stored in the content memory 1702 is denoted by C, the
first cipher key that is stored in the first cipher key memory 1703
is denoted by FK, and the first encrypted content 1705 is denoted
by C[FK]. Then, the following equation can be represented:
C*FK=C[FK] (10).
[0233] The CATV decoder 1706 transmits, to the control section
1707a of the key issuing center apparatus 1707 via the network, a
system ID that is stored in the system ID memory 1708 of the CATV
decoder 1706, and a title code 1709 of the above-mentioned content
which user wishes to watch and listen to, where the title code 1709
is inputted by using, for example, a keyboard (not shown). The
above-mentioned title code 1709 may be inputted by selecting
according to the screen of the television set 1730, the title code
1709 may be inputted directly by using the keyboard, or the title
code 1709 may be inputted from the remote controller or the like.
Accordingly, the title code 1709 may be obtained by a user in his
own way, the title code 1709 may be sent from the CATV decoder 1706
together with the first encrypted content, or the title code 1709
may be sent in advance at a different time from that of the first
encrypted content in a form of program guidance or the like.
[0234] Based on the system ID of the CATV decoder 1706 and the
title code 1709 of the above-mentioned content, the control section
1707a of the key issuing center apparatus 1707 generates the
corresponding key (K) 1712 with reference to the corresponding time
limitation information that is stored in the time limitation
information memory 1710, and then, transmits the generated key (K)
1712 to the first cipher decoder 1713 of the CATV decoder 1706 via
the network. The time limitation information makes it possible to
distinguish from among the cases where the same content is
broadcasted a plurality of different times. The first decipher key
is denoted by FK, the system ID of the CATV decoder 1706 is denoted
DID, the time limitation information is denoted by TIME, and the
title code 1709 of the content is denoted by T, the key (K) 1712
satisfies the relationship represented by the following
equation:
FK=K*T*DID*TIME (11).
[0235] The first cipher decoder 1713 can decrypt the first
encrypted content 1705 if the first decipher key (FK), the
above-mentioned key (K) 1712 transmitted from the key issuing
center apparatus 1701, the title code (T) 1709 of the
above-mentioned content, the system ID (DID), and the time
limitation information (TIME) satisfy the above-mentioned
relationship, and if the time limitation information (TIME)
satisfies the condition of the present time information from the
clock circuit 1725. In this case, when the first encrypted content
1705 is an image signal, the descrambled image signal is outputted
to the television set 1730 from the first decipher decoder 1713 so
that the user can watch and listen to the content on the television
set 1730. In this case, the decrypting process of the first cipher
decoder 1713 is expressed as follows:
C[FK] #(K*T*DID*TIME) C[FK] # FK C (12)
[0236] Next, the method for recording the above-mentioned content
on the optical disk 1601 will be described. When the content is
recorded on the optical disk 1601, the first encrypted content 1705
which has not been decrypted by the CATV decoder 1706 is
transmitted to the recording circuit 1717 of the optical disk
recording and reproducing apparatus 1714 from the first cipher
encoder 1704 of the CATV company apparatus 1701. The recording
circuit 1717 digitally modulates data of the received first
encrypted content 1705 by using a modulation system such as a
well-known 8/16 modulation system, and the modulated digital data
are recorded on the optical disk 1601 by the optical pickup (not
shown). Accordingly, it is necessary for the first encrypted
content 1705 to be decrypted so as to reproduce the above-mentioned
content that are encrypted and recorded on the optical disk
1601.
[0237] The optical disk recording and the reproducing apparatus
1714 transmits, to the control section 1707a of the key issuing
center apparatus 1707 via the network, the disk ID signal 1715 of
the optical disk 1601 that is reproduced by the BCA reproducing
circuit 1720 and the title code 1716 of the above-mentioned
content, which is inputted by using, for example, a keyboard (not
shown) and which the user wishes to reproduce. As to the timing for
sending the disk ID, the disk ID may be sent when the key issuing
center apparatus 1707 is accessed, or the disk ID may be sent
together with the title code when listening and watching the
content.
[0238] Although, as a method for transmitting the disk ID, a method
for sending the output signal from the BCA reproducing circuit 1720
directly to the key issuing center apparatus 1707 by reproducing
the BCA 1604 of the optical disk 1601 as shown in FIG. 22 is
disclosed above, the present invention is not limited thereto, and
the following method maybe used. For example, the data of the BCA
1604 is reproduced before access to the key issuing center
apparatus 1707 when starting up the disk, and the data of the BCA
1604 is stored in a memory (not shown) of the optical disk
recording and reproducing apparatus 1714 or the CATV decoder 1706,
and then, the data of the BCA1604 is transmitted to the control
section 1707a of the key issuing center apparatus 1707 at the
above-mentioned timing. In addition, when the disk ID can be
recognized visually, in some form such as a label, a keyboard may
be used for inputting the disk ID. When the label is a bar code, a
bar code reader may be used for reading out the disk ID.
[0239] The control section 1707a of the key issuing center
apparatus 1707 generates a key (DK) 1718 corresponding to the disk
ID signal 1715 of the optical disk 1601 and the title code 1716 of
the content, and transmits the generated key (DK) 1718 to the key
information recording circuit 1719 of the optical disk recording
and reproducing apparatus 1714. In this case, the first decipher
key is denoted by FK, the disk ID signal 1715 of the optical disk
1601 is denoted by BCAS, and the title code 1716 of the content is
denoted by T, whereby the key (DK) satisfies the relationship of
the following equation:
FK=DK*BCA*T (13).
[0240] The key (DK) that is inputted into the key information
recording circuit 1719 of the optical disk recording and
reproducing apparatus 1714 is digitally modulated by using a
modulating system such as the well-known 8/16 modulation system or
the like, and then, the modulated digital data is recorded in the
key information recording area 1605 on the optical disk 1601 by the
optical pickup (not shown). The key (DK) may be recorded a
plurality of times in the key information recording area 1605. By
recording the same key a plurality of times, the key (DK) can be
protected when the recording film of the key information recording
area 1605 deteriorates or when the optical disk 1601 gets
scratched, and as a result, the content can be decrypted only when
the data of either one of the keys (DK) can be reproduced.
[0241] Although, in the fifth preferred embodiment, the key
information recording area 1605 is provided on the inner peripheral
side of the user data area 1603, the key information recording area
1605 may be provided on the outer peripheral side of the user data
area 1603, or the key information recording area 1605 may be
provided both on the inner periphery and the outer peripheral
sides. By providing the key information recording area 1605 on the
outer peripheral side, it becomes possible to record more keys
(DK). Also, by dispersedly providing a plurality of key information
recording areas, the key (DK) can be protected by the other key
information recording areas even in the case where one key
information recording area cannot be reproduced.
[0242] On the other hand, a laser beam that is outputted from the
optical pickup is irradiated onto the area of the optical disk 1601
on which the above-described content is recorded so that the
reflected light enters into the optical pickup. The optical pickup
photoelectrically converts the entered reflected light into a
reproduced electric signal, and the reproduced signal which has
been photoelectrically converted is outputted to the data
reproducing section 1721. In response to this, the data reproducing
section 1721 A/D converts the inputted reproduced signal into
encrypted digital data, which is outputted to the second cipher
decoder 1722. In addition, a laser beam that is outputted from the
optical pickup is irradiated onto the BCA 604 of the optical disk
1601, and then, the reflected light enters the optical pickup. The
optical pickup photoelectrically converts the inputted reflected
light into a reproduced electric signal, and the reproduced signal
which has been photoelectrically converted is outputted to the BCA
reproducing circuit 1720. In response to this, the BCA reproducing
circuit 1720 reproduces the disk ID signal 1715 based on the
inputted reproduced signal, which is outputted to the encryption
decoder 1722. In addition, a laser beam that is outputted from the
optical pickup is irradiated onto the key information recording
area 1605 of the optical disk 1601 so that the reflected light
enters the optical pickup. The optical pickup photoelectrically
converts the entered reflected light into a reproduced electric
signal, and outputs the reproduced signal to the key information
reproducing section 1723. In response to this, the key information
reproducing section 1723 generates data of a key (DK) based on the
inputted reproduced signal, which is outputted to the second cipher
decoder 1722.
[0243] When the content is reproduced immediately after access to
the key issuing center apparatus 1707, the key information
recording circuit 1719 may directly input the key (DK) to the
second cipher decoder 1722 before recording the same key (DK) in
the key information recording area 1605. By doing this, the time
until the reproduction is started can be shortened. The cipher
decoder 1722 decrypts the encrypted content by using the decipher
key including the inputted disk ID signal 1715, the key (DK) and
the title code 1716 of the above-described content. The decrypting
process of the second cipher decoder 1722 is expressed in the
following equation. When the content is an image signal, an MPEG
signal is, for example, expanded so that an output signal 1724 of
the image signal is outputted from the second cipher decoder 1722.
2 C [ FK ] # ( DK * BCA * T ) = C [ FK ] # FK = C ( 14 )
[0244] In the fifth preferred embodiment, when a user fee is
imposed when the key signal is received from the control section
1707a of the key issuing center apparatus 1707, a fee is separately
imposed when listening and watching the content, and the content
that is recorded on the optical disk 1601 is reproduced for the
first time, which avoids the fee imposition only upon recording the
content data on the optical disk 1601. Accordingly, it becomes
possible to lower the imposed fee,
[0245] (a) for the users who wish to listen and watch content, but
do not need to record content data on the optical disk 1601, or
[0246] (b) for the users who wish to record content data on the
optical disk 1601, but who do not need to listen and watch content
upon broadcasting,
[0247] as compared with the case in which a fee is imposed once for
both listening or watching and recording on the optical disk
1601.
[0248] Also, since a fee is not imposed for only recording on the
optical disk 1601, the user can determine whether or not the user
receives the key for reproducing the optical disk 1601 to listen
and watch again after listening and watching. Although, in the
above-mentioned fifth preferred embodiment, a method for receiving
the key (DK) from the control section 1701a of the key issuing
center apparatus 1707 via the network is used, the present
invention is not limited thereto. For example, the title and the
disk ID number of the content may be orally conveyed over the phone
or the like, and be inputted by using a keyboard after being
received orally.
[0249] Next, the case will be described where the optical disk
1601, on which the key (DK) is recorded in the key information
recording area 1605, is reproduced after access to the key issuing
center apparatus 1707 is completed. First of all, a laser beam that
is outputted from the optical pickup is irradiated onto the area of
the optical disk 1601 where the above-mentioned content is
recorded, and then, the reflected light is inputted to the data
reproducing section 1721 via the optical pickup which carries out
the photoelectric conversion. In response to this, the data
reproducing section 1721 outputs the data of the encrypted content
to the second cipher decoder 1722. On the other hand, a laser beam
that is outputted from the optical pickup is irradiated onto the
BCA 1604 of the optical disk 1601 so that the reflected light is
inputted into the BCA reproducing circuit 1720 via the optical
pickup which carries out the photoelectric conversion. In response
to this, the BCA reproducing circuit 1720 generates the disk ID
signal 1715 based on the inputted reproduced signal, which is
outputted to the second cipher decoder 1722.
[0250] In addition, the laser beam that is outputted from the
optical pickup is irradiated onto the key information recording
area 1605 of the optical disk 1601 so that the reflected light is
inputted into the key information reproducing section 1723 via the
optical pickup which carries out the photoelectric conversion. In
response to this, the key information reproducing section 1723
generates data of the key (DK) based on the inputted reproduced
signal, which is outputted to the second cipher decoder 1722. The
second cipher decoder 1722 decrypts the encrypted content outputted
from the data reproducing section 1721 by using the decipher key
including the inputted disk ID signal 1715, the key (DK) and the
title code 1716 of the above-mentioned content. The decoding
process of the second cipher decoder 1722 is expressed in the
following equation. When the content is an image signal, an MPEG
signal is, for example, expanded, and the image signal of the
expanded MPEG signal is outputted from the second cipher decoder
1722. 3 C [ FK ] # ( DK * BCA * T ) = C [ FK ] # FK = C = C ( 15
)
[0251] By recording the data of the key (DK) once in the key
information recording area 1605, the above-mentioned encrypted
content can always be reproduced without any access to the key
issuing center apparatus 1707. Also, since all of the decipher keys
that are required for the decrypting process are recorded on the
optical disk 1601, the above-mentioned optical disk 1601 can be
reproduced by an arbitrary optical disk recording and reproducing
apparatus comprising the BCA reproducing circuit 1720, the key
information reproducing section 1723 and the second cipher decoder
1722.
[0252] In addition, in the case where the above-mentioned encrypted
content is attempted to be reproduced after being copied onto the
optical disk 1601 with a different disk ID, a disk ID signal that
is different from that of the above-mentioned optical disk 1601 is
outputted from the BCA reproducing circuit 1720, and therefore, the
encrypted content cannot be decrypted, which thereby prevents the
content from being reproduced after being copied. Even in this
case, however, by conveying the title and the disk ID of the
content to the key issuing center through the network or orally,
the decipher key may be received after the fee is imposed. In this
way, even if the encrypted content is copied onto another optical
disk 1601, content cannot be reproduced irregularly, and a fee is
always imposed when the optical disk 1601 on which the encrypted
content is copied, is reproduced, which thereby leads to the
protection of the copyright for the content.
[0253] FIG. 23 shows a table showing a configuration of the table
with IDs according to the fifth preferred embodiment, where the
table shows keys (K) that are inputted into the first cipher
decoder 1713 and keys (DK) that are inputted into the key
information recording circuit 1719 in a rearranged form for
different system IDs and different disk IDs.
[0254] Referring to FIG. 23, T1, T2 and T3 denote title codes for
different contents, and FK1, FK2 and FK3 denote decipher keys for
decoding encrypted contents having the title codes of T1, T2 and
T3, respectively. DID1, DID2 and DID3 denote system IDs for
different CATV decoders 1706, and BCAS1, BCAS2 and BCAS3 denote
disk IDs for different optical disks 1601. In this case, keys (Kmn)
that are inputted into the CATV decoder 1706 are determined so as
to satisfy the following equation:
FKn=Kmn*Tn*DID*TIMEn (16).
[0255] Also, the keys (DKmn) that are inputted to the optical disk
recording and reproducing apparatus 1714 are determined so as to
satisfy the following equation:
FKn=DKmn*BCAm*Tn (17).
[0256] As shown in FIG. 23, not only in the case of different
content but also in the case of the same content, the key
information that is acquired from the key issuing center apparatus
1707 for each different CATV decoder 1706, for each different
optical disk and for each different broadcasting time is set so as
to be different from each other, and then, this leads to protection
of the copyright in detail. In the same way, since the key
information differs when the system IDs, the disk IDs and the time
information are different from the others even for the same
content, it is not necessary for the CATV company apparatus 1701 to
change the encrypted content for each user, therefore, one
encrypted content maybe prepared for one content. Therefore, the
system for broadcasting can be simplified, and it becomes possible
to supply the content to a mass audience at a low cost.
[0257] Although, in the fifth preferred embodiment, the case
described where the content is broadcasted from a head end of the
cable television, the present invention can be applied to
broadcasting by using a radio wave.
Advantageous Effects of Third to Fifth Preferred Embodiments
[0258] An optical disk according to the present preferred
embodiments comprises (a) a first information area for recording
first disk information therein, (b) a second information area for
recording therein second disk information for identifying
individual, and (c) a user data area in which recording information
is possible by irradiating a light beam onto the user data area.
Accordingly, by adding the above-mentioned information for
identifying optical disks to an optical disk according to the prior
art, the management of optical disks can be easily implemented. In
this case, the above-mentioned second information area is
preferably recorded in the above-mentioned first information area,
and can be reproduced by the optical pickup for reproducing the
above-mentioned first information area. In the above-mentioned
second information area, data of the second information is recorded
by partially eliminating or removing the recording film within the
above-mentioned first information area so that a plurality of
trimming areas having an elongated shape in the radius direction
are formed, and this can prevent the above-mentioned second disk
information from being easily falsified.
[0259] According to a method for recording encrypted content of the
present preferred embodiments, when the data of the content is
recorded on the user data area of an optical disk comprising (a) a
first information area for recording the first disk information
therein, (b) a second information area for recording therein the
second disk information for identifying individual disks, and (c) a
user data area in which recording information is recorded by
irradiating a light beam onto the user data area, the data of the
content is encrypted and the encrypted data is recorded so that the
data of the content can be decrypted and reproduced by an operation
or calculation using at least the above-mentioned second disk
information. Accordingly, by encrypting the content using the
identification information of an optical disk which exists only in
one particular optical disk, there is such a specific advantageous
effect that irregular copying of the content can be prevented so as
to protect the copyright.
[0260] An optical disk according to the present preferred
embodiments has a key information recording area for recording
therein key information for decrypting encrypted and recorded
content within the user data area. Accordingly, in a system which
needs key information for decrypting the encrypted and recorded
content, there is such a specific advantageous effect that it is
not necessary to input key information each instance of
reproduction after recording the key information once in the key
information recording area.
[0261] Furthermore, according to a method for recording encrypted
content of the present preferred embodiments, when the content is
recorded in the user data area of an optical disk comprising (a) a
first information area for recording the first disk information
therein, (b) a second information area for recording therein the
second disk information for identifying individual disks, (c) a
user data area in which information is recorded by irradiating a
light beam onto the user data area, and (d) a key information
recording area for recording therein key information for decrypting
the data of the encrypted and recorded content within the user data
area, the data of the content is encrypted and the encrypted
content is recorded so that the data of the content can be
decrypted and reproduced by the operation using at least the
above-mentioned second disk information and the above mentioned key
information. Accordingly, even if the data of the encrypted content
are copied onto another optical disk, the data thereof cannot be
reproduced irregularly, and a fee is always imposed whenever the
optical disk on which the data of the encrypted content are copied
is reproduced, which thereby leads to the protection of the
copyright.
[0262] In this case, the first disk information is preferably
formed in a form of micro concavo-convex pits, and the second disk
information for identifying optical disks is recorded on the
concavo-convex pits. Therefore, the second disk information can be
easily prevented from being falsified. Moreover, the first disk
information and the second disk information are preferably formed
to be adjacent from each other. In this case, when the
above-mentioned first disk information is reproduced, the second
disk information can be reproduced continuously, or when the second
disk information is reproduced, the first disk information can be
reproduced continuously. Therefore, it becomes possible to
accelerate the process for recording the encrypted content after
obtaining or acquiring the second disk information for identifying
disks quickly by a CPU when, for example, the optical disk is
started up.
[0263] According to a method for recording encrypted data of the
present preferred embodiments, since key information differs for
each different system ID, each disk ID and each time information
even with the same content, it is not necessary for the CATV
company apparatus 701 to change the encrypted content for each
user, and then, the CATV company apparatus 701 may only prepare one
encrypted content for one content. This leads to the system for
broadcasting being simplified, and it thereby becomes possible to
supply the content to a mass audience at a low cost.
Modified Preferred Embodiments of Third and Fifth Preferred
Embodiments
[0264] Although in the above-mentioned third and fifth preferred
embodiments, as shown in FIGS. 16 and 21, trimming areas 1105 and
1606 are formed in the BCAs 1104 and 1604 which are located in the
inner periphery section within the control user data areas 1102 and
1602, respectively, the present invention is not limited thereto.
As shown in FIGS. 24 and 25 which illustrate the data recording
areas of the optical disks 1101a and 1601a according to the
modified preferred embodiments of the third and the fifth preferred
embodiments, respectively, the trimming areas 1105a and 1606a may
be formed by trimming the recording film so as to protrude or
project into the inner peripheral side of the optical disk from the
control user data areas 1102 and 1602. That is to say, the BCAs
1104a and 1604a are not included in the control user data areas
1102 and 1602, respectively, but are formed and allocated so as to
protrude or project into the inner side of the control user data
areas 1102 and 1602 from the inner peripheral section of the
control user data areas 1102 and 1602. In these modified preferred
embodiments, the reason why the BCAs 1104a and 1604a are formed in
this way is that the margin is taken into consideration where the
diameter of the beam spot of the laser beam fluctuates due to the
instability of the focusing servo circuit of the laser device. In
the present modified preferred embodiments, the user data areas
1103 and 1603 exist outside of the control user data areas 1102 and
1602. Therefore, the trimming areas 1105a and 1606a are allocated
and formed so as to protect the data recorded in those user data
areas 1103 and 1602 from being destroyed.
Sixth Preferred Embodiment
[0265] FIG. 26 shows a block diagram illustrating a configuration
of a user data area within an optical disk and a configuration of
an optical disk reproducing apparatus for decrypting an encrypted
content from data in the user data area according to a sixth
preferred embodiment of the present invention. In the sixth
preferred embodiment, the optical disk is, for example, a
recording-type optical disk such as a DVD-RAM.
[0266] As shown in FIG. 26, a user data area 2150 comprises a
sector header area 2101, a main data area 2102, and an error
detection code 2103. In the sector header area 2101, a sector
address 2104 for indicating a sector position, and copyright
control information 2105 for recording the copyright control
information (including a scramble flag, copy control information or
the like) with respect to the data recorded in the main data area
2102 are recorded. The sector head area 2101 includes a decipher
key area 2106 for decrypting encryption information when such
information has been embedded or encrypted in the data of the main
data area 2102. Also, the main data area(s) 2102 is/are divided
into an area in which non-encrypted content 2107 is recorded and an
area in which the encrypted content 2108 is recorded, and the
non-encrypted content 2107 includes control information for
subsequent data such as synchronizing patterns in the MPEG or all
types of control information. In addition, the encrypted content
2108 includes content data that are required for copyright
protection primarily such as AV data or the like which have been
encrypted.
[0267] The decipher key for reproducing the following main data
area 2102 is divided into a plurality of divided decipher keys with
a predetermined size (hereinafter referred to as divided decipher
keys), which are then registered in the decipher key area 2106. For
example, in the case where the decipher key is 8 bytes for one
decipher key area of 4 bytes, the decipher key of 8 bytes is
divided into two divided decipher keys each of 4 bytes so that the
two divided decipher keys are recorded in decipher key areas 2106
and 2109 of two logically continuous sectors after dividing the
decipher key of 8 bytes into divided decipher keys each of 4 bytes.
When reproducing data of such a user data area, a plurality of
divided decipher keys are acquired from the decipher key areas 2106
and 2109 of the logically continuous plurality of sectors (each
sector which is not available due to defects is skipped), and the
acquired divided decipher keys of the required number are linked or
connected by a data linking device 2111 so as to obtain the
encrypted decipher key that is required for the reproduction (8
bytes). A decrypting process is carried out for the data that are
recorded in the main data area 2102 of the sector where the
encrypted decipher keys (8 bytes) could be obtained by a decrypting
device 2114 in accordance with the contents of each unit of
copyright control information 2105.
[0268] In addition, to further enhance the intensity of the
encryption, it is possible to encrypt the decipher key, or by
adding the decipher key conversion data which is the information in
the data to the key so as to not have a constant result of the
encryption, it becomes possible to provide different encryption
results even for the same cipher key. More concretely, as shown in
FIG. 26, the encrypted decipher key that is outputted from the data
linking device 2111 is inputted to the key decrypting device 2112,
and then, by using a predetermined disk key, the key decrypting
device 2112 decrypts the inputted encrypted decipher key into the
padding data (1 byte) which are dummy data and the decipher key (7
bytes), which are then outputted to the key converter 2113. In this
case, the disk key is acquired by decrypting, for example, an
encrypted disk key that is recorded in the optical disk by using a
secret key which is a predetermined master key by the disk key
decrypting device (not shown). Also, the key converter 2113
converts data of the decipher key conversion data 2110 that are
read out from the main data area 2102 through a predetermined
conversion operation such as an operation utilizing multiplication,
division or predetermined weighting coefficients by using the
decipher key outputted from the above-mentioned key decrypting
device 2112, and then, generates and outputs a content decipher key
(7 bytes) to the decrypting device 2114. Then, the decrypting
device 2114 generates and outputs the data of the decrypted content
by decrypting the data of the content that are read out from the
main data area 2102 using the content decipher key (7 bytes)
outputted from the above-mentioned key converter 2113. As the
decipher key conversion data 2110, it is preferable to utilize the
data such as data whereby the irregular usage of the data such as
falsifying the copy generation management information or the analog
macro-vision control flag can be immediately detected.
[0269] FIG. 27 is a block diagram showing an arrangement of the
copyright control information and the decipher key in the user data
area and an allocation of the encrypted content in the main data
area of an optical disk according to the sixth preferred
embodiment. In an example of the user data area 2150 illustrated in
FIG. 27, the decipher key area is arranged so as to be divided into
the first decipher key area 2201 having a division decipher key of
4 bytes and the second decipher key area 2202 having a division
decipher key of 4 bytes. Therefore, in spite of the size of the
encrypted content that are recorded in those two sectors, a
plurality of sectors (2 sectors in FIG. 27) are utilized. In this
case, dummy data is recorded in the unused area as complementary
data. In an example of FIG. 27, complementary data 2203 for one
sector is recorded in the case that the encrypted content 2204
exits only for one sector.
[0270] FIG. 28 is a block diagram showing an arrangement of the
case where the unit of error correction is located over a plurality
of sectors in an optical disk according to the sixth preferred
embodiment. For example, in the case where the optical disk is a
DVD, the ability of error correction is enhanced by using a unit
block (hereinafter referred to an ECC block) of error correction
code of 16 sectors. Therefore, when data recording or reproducing
is carried out, it is necessary to perform the recording process by
using the ECC block unit. In the case where the decipher key is
divided into an arbitrary number of divided decipher keys which are
then recorded, the case may exist where one decipher key is
recorded in a plurality of error correction blocks. When
reproducing the same, it is necessary to reproduce all of the
plurality of divided decipher keys. Therefore, it is also necessary
to reproduce not only data in the sector for recording the data of
the encrypted content but also data in the ECC block immediately
before a decipher key is recorded. An example of FIG. 28 is
characterized in that the number of divisions when the decipher key
is divided is set as a measure or factor of the number of sectors
of the ECC blocks. As a result, a plurality of divided decipher
keys cannot be recorded so as to located over a plurality of ECC
blocks. In addition, as a decipher key used in one ECC block, only
one type of decipher key is used, and in the case where the
recorded AV data are not sufficient for an ECC block, the data of
the sectors which are unnecessary upon reproduction can be
prevented from being read out from the optical disk by arranging
complementary data and complementary sectors.
Seventh Preferred Embodiment
[0271] FIG. 29 is a block diagram showing a configuration of a
lead-in (rewritable) area 2401 and a user data area 2402 within an
optical disk and a configuration of an optical disk reproducing
apparatus for decrypting an encrypted content from data of the
lead-in area 2401 and the user data area 2402 according to the
seventh preferred embodiment of the present invention.
[0272] Referring to FIG. 29, in the same way as in that of the
sixth preferred embodiment of FIG. 26, each of the lead-in area
2401 and the user data area 2402 is constructed from sectors having
a sector header area 2101, the main data area 2102 and an error
detection code 2103. In the sector header area 2101, there are
recorded a sector address 2104 for indicating the position of the
sector and copyright control information 2105 for recording
copyright control information (including a scramble flag, copy
control information or the like) with respect to the data that are
recorded in the main data area 2102. Further, the sector header
area 2101 includes a key index area 2403 for recording a key index
for indicating the recording position of the decipher key (that is,
the recording position of storing position in a decipher key table
2404 within the main data area 2102) for referring to a decipher
key for decrypting in the case where the data of the main data area
2102 are encrypted. The decipher key for decrypting the encrypted
content recorded in the user data area 2402 is recorded in a form
of a decipher key table 2404 in the lead-in area 2401 which is
rewritable in a form of a table. The decipher key that is recorded
in the lead-in area 2401 is referred to by the key index that is
recorded in the key index area 2403. In the same way as that of the
sixth preferred embodiment illustrated in FIG. 26, the decipher key
referred to as described above is decrypted into the padding data
and the decipher key (or title key) by the key decrypting device
2112 using a predetermined disk key, and thereafter, the
above-mentioned decrypted decipher key (or title key) is converted
into a content decipher key by the key converter 2113 using the
decipher key conversion data, and then, the converted content
decipher key is outputted to the decrypting device 2114. The
decrypting device 2114 decrypts the data of the encrypted content
by using the content decipher key, and then, generates and outputs
data of the decrypted content.
[0273] In an optical disk and an optical disk reproducing apparatus
according to the seventh preferred embodiment constituted as
described above, by recording a key index for reference in the key
index area 2403 within the sector header area 2101, it becomes
possible to allocate the decipher key size of the decipher key
table 2404 independently from the size of the key index area 2403.
Also, after allocating the size of the decipher key table 2404, by
utilizing a plurality of decipher keys continuously from the
decipher key table 2404 indicated by the key index within the key
index area 2403, a decipher key of an arbitrary or free size can be
used.
[0274] FIG. 30A is a block diagram showing a data configuration of
the case where an initial value of a decipher key represents an
unrecorded status in the main data area 2102 of the lead-in area
2401 within an optical disk according to the seventh preferred
embodiment. Referring to FIG. 30A, as the initial value of the
decipher key recorded upon formatting of the optical disk or the
like, the data in the unrecorded status 2501 is recorded with an
already known fixed value (for example, data such as all zeros)
which are not used as a key to thereby indicate the unrecorded
status of the decipher key.
[0275] FIG. 30B is a block diagram showing a data configuration of
the case where a recorded status is represented with a decipher key
status table in the main data area 2102 of the lead-in area 2401
within an optical disk according to the seventh preferred
embodiment. Referring to FIG. 30B, in the same way as that of the
decipher key illustrated in FIG. 30A, the decipher key status table
2502 in a form of table which can be referenced by an index is
arranged in the lead-in area 2401, and the recorded status of the
decipher key is described as follows as record status data
2503:
[0276] (1) 0x00: unused;
[0277] (2) 0x01: area reservation;
[0278] (3) 0x03: key recorded; and
[0279] (4) otherwise: reserved.
[0280] In this case, Ox indicates a hexadecimal representation of
the following symbols or numbers.
[0281] FIG. 31 is a block diagram showing an allocation of decipher
keys in an optical disk according to the seventh preferred
embodiment. In an example of FIG. 31, an allocation of the decipher
key area of the disk is devised so as to enhance the reliability of
the decipher keys. Usually, defect management is carried out in the
user data area 2602, and therefore, in the case where a write
failure occurs, a replacement process for an area to be replaced or
the like is carried out. In the lead-in area 2601, however, the
defect management as described above is not carried out. Therefore,
by occurrence of a write-in failure, a read-out failure or the
like, the decipher key, which is required for producing the AV
data, may be converted into an unusable status, and moreover, there
may be the case where the optical disk itself may be converted into
an unusable status. Accordingly, a total plurality of decipher keys
are desired to be recorded over a plurality of different ECC
blocks. In the case where a plurality of decipher keys are recorded
in areas adjacent to each other, all of the entire plurality of
decipher keys which have been recorded may not be read out due to
scratches or dust. Therefore, as shown in FIG. 31, it is preferable
to record in separate positions in a layout, such as the inner
peripheral side and the outer peripheral side of the optical disk,
respectively, for example, in the lead-in area 2601 and the
lead-out area 2603.
[0282] In the seventh preferred embodiment of FIG. 29, the decipher
key areas are allocated in the lead-in areas 2401 and 2601. This is
because to enhance the safety when access is taking place from a
drive unit of a personal computer or the like, with taking into
consideration that the user data area 2602 is an accessible area by
a conventional read command or write command. Accordingly, the same
advantageous effects can be obtained by allocating these in the
user data area 2602.
Eighth Preferred Embodiment
[0283] FIG. 32 is a block diagram showing a data configuration when
data of an optical disk is managed by a file management system of
an eighth preferred embodiment according to the present invention.
In an example of FIG. 32, based on a structure of the file system,
a sector address for storing a desired file is managed.
[0284] In the structure of a file system which is prescribed or
regulated in the ISO 13346 by the International Standardization
Organization, a recording position of a file is managed by using
the information called a file entry in order to utilize a
rewritable-type optical disk. As shown in FIG. 32, for example,
data of a recording position of a file (1) 2703 is stored as a file
entry (1) 2701 within a file management information area 2751, and
data of a recording position of a file (2) 2704 is stored as a file
entry (2) 2702. Each file is constituted from extents 2705 and 2706
for managing a plurality of sector areas which are located so as to
continue on the optical disk. The encrypted content as shown in the
seventh preferred embodiment is recorded in the main data area 2102
indicated by the file entry on the optical disk, and the decipher
key is recorded in the decipher key table 2707 within the lead-in
area 2601. In the sector header area 2101 within the user data area
2602 where the encrypted content is recorded, a pointer for
indicating a recording position for referring to a decipher key
that is required for decrypting is recorded in the key index area
2708. Although, in the eighth preferred embodiment, the decipher
key is managed and recorded using the file unit, the extent unit,
the present invention is not limited thereto. The decipher key may
be managed and recorded by using at least one of either of the file
unit or the extent unit.
[0285] As described above in the optical disk, managed by the file
system, the recording operation of the content required for
copyright protection will be described with reference to FIG. 33.
FIG. 33 shows a recording process of a content required for
copyright protection carried out by a file management system
according to the eighth preferred embodiment.
[0286] When recording the encrypted content, first of all, in step
S2801, the decipher key status table 2502 illustrated in FIG. 30B
is read out so as to check empty areas of the decipher key table
2707. Next, in step S2802, it is determined whether or not there is
any empty areas of the decipher key table 2702, and in the case of
NO, the recording process of the content is completed by stopping
the recording operation in step S2807 because the decipher key for
the encrypted content cannot be recorded. On the other hand, in the
case of YES in step S2802, the acquired decipher key (or the title
key) is recorded, and in the case where the decipher key cannot be
acquired, the decipher key area is reserved. Next, in step S2804,
the copyright control information of the recorded content
(including information about whether or not encryption has been
performed, information for indicating the type or class of
encryption or the like) and the key index to be recorded in the key
index area 2708 are set, and thereafter, the content is encrypted
in step S2805 and then the encrypted content is recorded on the
optical disk in a file form using the extent unit. In this case,
the same copyright control information and key index may be used by
utilizing the file unit or they may be switched by utilizing the
extent unit. That is to say, in steps S2804 and S2805, the unit to
be processed is at least one of either the file unit or the extent
unit. Finally, in step S2806, based on the information with respect
to the recorded content, after the file management information for
managing the above-mentioned recorded data is updated, the
recording process of the content is completed.
[0287] FIG. 34 is a flowchart showing a reproducing process of
content that is carried out by a file management system according
to the eighth preferred embodiment. FIG. 34 shows a process for
reproducing the content recorded in a form of file from the optical
disk by the method shown in FIG. 33.
[0288] When carrying out a reproducing operation for the file, the
key index is acquired for the areas shown by the file entry within
the file management information area 2751 so as to find out or know
the area in the decipher key table that is utilized by the
reproduced file. More concretely, in step S2901, after the file
entry of the file that is reproduced from the file management
information 2751 is acquired by being read out and reproduced, the
value of the key index area is read out in step S2902, and is then
reproduced from the sector header area 2102 of the area shown by
the file entry to be acquired. In the case where different ways of
encrypting are conducted by utilizing the extent unit, the key
index area in the sector header for each extent is read out. Then,
in step S2903, the decipher key is read out, and is then reproduced
so as to acquire the decipher key from the decipher key area of the
decipher key table 2707 that is indicated by the acquired key
index. In addition, in step S2904, the data of the content within
the file is read out and reproduced from an area shown by the file
entry, and then, data of the reproduced content is decrypted. In
this case, when reproduction and the decrypting of the file of the
content are completed, the reproducing process of the content is
completed.
[0289] FIG. 35 is a flowchart showing a deleting process of content
which is carried out by the file management system according to the
eighth preferred embodiment, and FIG. 35 shows an operation for the
deletion of data of content in a form of file which has been
recorded by the method as shown in FIG. 33.
[0290] When the deleting operation of the file is carried out, the
key index for the area shown by the file entry is acquired so as to
find out or know the areas of the decipher key table 2707 that are
used by the deleted file. More concretely, in step S3001, after
acquiring the file entry of the deleted file from the file
management information within the file management information area
2751, the value of the key index area is acquired from the sector
header of an area that is indicated by the file entry in step
S3002. In this case, when different ways of encrypting are
conducted by utilizing the extent unit, data in the key index area
in the sector header for each extent is read out. Then, in step
S3003, after the decipher key is open or released (here, releasing
or opening the decipher key means to delete the decipher key from
the table) from the decipher key area of the decipher key table
2707 that is indicated by the acquired key index, and, in step
S3004, the file entry for indicating the write-in position of the
deleted file is deleted from the file management information. Then,
the deleting process of the content is completed. Although only the
file entry is deleted when the file is deleted in a conventional
file system, the decipher key that is recorded in another area
cannot be deleted since the decipher key and the record sector of
the encrypted content are recorded in separate areas. In the
above-mentioned preferred embodiments, prior to the deletion of the
file entry, the management of the decipher key on the optical disk
is carried out by deleting the decipher key for indicating the key
index in the sector header area from the decipher key table
2707.
Ninth Preferred Embodiment
[0291] FIG. 36 is a block diagram showing a configuration of an
optical disk system of a ninth preferred embodiment according to
the present invention, and this optical disk system is a
information processing system for recording and reproducing content
that is required for copyright protection of the optical disk 3100.
The optical disk system comprises an encoding apparatus 3101, an
optical disk apparatus 3102, a decoding apparatus 3103, and a
personal computer 3104.
[0292] The encoding apparatus 3101 comprises a content memory 3131
for storing data of content, an encoding circuit 3132 for encoding
the above-mentioned data of the content in a form of MPEG format, a
cipher key memory 3133 for storing the cipher key, an encrypting
circuit 3134 for encrypting the data of the encoded content by
utilizing the cipher key and generating and storing the decipher
key in the decipher key memory 3111, a decipher key memory 3111 for
storing the decipher key, a bus encryption circuit 3112 for
bus-encrypting the decipher key, and an interface 3124 which is
connected to the interface 3122 of the personal computer 3104 via a
PCI bus 3151, where the interface 3124 transmits the data of the
encrypted content and the decipher key. Also, the optical disk
apparatus 3102 comprises a decipher key table memory 3113 for
storing a plurality of decipher keys therein, a bus encrypting and
decrypting circuit 3114, a recording and reproducing circuit 3119
for recording the data onto the optical disk 3100 and for reading
out and reproducing the data from the optical disk 3100, and an
interface 3120 which is connected to the interface 3121 of the
personal computer 3104 via a SCSI bus 3152, where the interface
3120 carries out processes such as the transmission and reception
of data or signals as well as signal conversion and protocol
conversion. The SCSI bus 3152 may preferably be an ATAPI bus. In
this case, bus encryption and bus decryption mean the cipher
process and the decipher process, respectively, which is used for
encrypting a cipher key or a decipher key and transmitting or
receiving the same key on the PCI bus 3151 or the SCSI bus
3152.
[0293] In addition, the personal computer 3104 comprises a control
section 3130 for controlling the operation of the personal computer
3104, a bus encryption decipher key table memory 3115 for storing a
plurality of bus encryption decipher keys therein, a decipher key
status table memory 3116 for storing data of a plurality of
decipher key statuses (indicating a recording status or condition
of a plurality of decipher key status, more concretely indicating
non-usage or unused, area reservation, key recorded, reserved or
the like) corresponding to the above-mentioned plurality of bus
encryption decipher >keys, an interface 3121 which is connected
to the interface 3120 or the optical disk apparatus 3102 via the
SCSI bus 3152, where the interface 3121 carries out processes such
as transmission and reception of the data and the signals as well
as signal conversion and protocol conversion, and an interface 3122
which is connected to the interface 3123 of the decoding apparatus
3103 and the interface 3124 of the encoding apparatus 3101 via the
PCI bus 3151, where the interface 3122 carries out processes such
as transmission and reception of the data or the signals as well as
signal conversion and protocol conversion. In addition, the
decoding apparatus 3103 comprises an interface 3123 which is
connected to the interface 3122 of the personal computer 3104,
where the interface 3123 carries out processes such as the
transmission and the reception of the data or the signals as well
as signal conversion and protocol conversion, a bus decrypting
circuit 3117 for bus-decrypting or bus-decoding the encryption
decipher key received by the interface 3123, a decipher key memory
3118 for storing the decipher key therein, and a decryption circuit
3141 for decrypting or coding the data of the encrypted content
that is received by the interface 3123 by using the decipher key of
the decipher key memory 3118 as well as generating an image signal
or a speech sound signal by carrying out the decoding process of
the MPEG format, where the generated image signal and speech sound
signal are outputted to a display apparatus 3105.
[0294] In the encoding apparatus 3101 of this optical disk system,
the encoding circuit 3132 encodes the data of the content such as
the AV data that are stored or inputted to the content memory 3131
in a form of the MPEG format, and the encrypting circuit 3134
encrypts the data of the above-mentioned encoded content by using
the cipher key within the encrypting key memory 3133 which is
generated so as to avoid an irregular usage of the content on a
personal computer 3104. Then, the encoding circuit 3132 transmits
the data of the encoded content to the optical disk apparatus 3102
via the interface 3124 and the personal computer 3104. In this
case, the data of the encrypted content is transmitted to the
recording and reproducing circuit 3119 via the PCI bus 3151, the
interface 3122 and the interface 3121 of the personal computer 3104
and the interface 3120 of the optical disk apparatus 3102 from the
interface 3124 of the encoding apparatus 3101. Then, the data of
the encrypted content is recorded on the optical disk 3100 by the
recording and reproducing circuit 3119 of the optical disk
apparatus 3102. Also, the recording and reproducing circuit 3119 of
the optical disk apparatus 3102 reproduces the data of the
encrypted content that are recorded on the optical disk 3100, and
then, transmits the data of the reproduced encrypted content to the
decrypting circuit 3141 via the interface 3120, the interface 3121
and the interface 3122 of the personal computer 3104 and the
interface 3123 of the decoding apparatus 3103. The decrypting
circuit 3141 of the decoding apparatus 3103 decrypts the encryption
for the data of the encrypted content, and carries out a decoding
process of MPEG format, and then, outputs an image signal or a
speech sound signal of the decoded content to a display apparatus
3105 and a speaker apparatus (not shown), respectively.
[0295] The encryption circuit 3134 of the encoding apparatus 3101
carries out the encryption for the data of the encoded content in a
form of the MPEG format by using the cipher key within the cipher
key memory 3133, and at the same time, generates and stores the
decipher key that is required upon reproduction in the decipher key
memory 3111. Although it is necessary to record the data of the
encoded content and the decipher key on the optical disk 3100, in
the case where the decipher key is handled as plain text on the
personal computer 3104, there is such a possibility that the
decoding of the data of the encrypted content may become easy by
reading out the decipher key from the optical disk 3100. In order
to avoid this, a mutual authorization is carried out between the
encoding apparatus 3101 and the optical disk apparatus 3102 and a
bus encryption is carried out by using a bus key which is mutually
shared.
[0296] That is to say, more concretely, the decipher key that is
stored in the decipher key memory 3111 is encrypted by a bus
encryption circuit 3112 of the encoding apparatus 3101, and
thereafter, the encrypted decipher key is stored in a bus
encryption decipher key table memory 3115 of the personal computer
3104 via the interface 3124, the PCI bus 3151 and the interface
3122. On the other hand, in the bus encrypting and decrypting
circuit 3114 of the optical disk apparatus 3102, the decoding of
the encrypted decipher key which is reproduced by the recording and
reproducing circuit 3119 from the optical disk 3100 is carried out,
and thereafter, the decipher key which has been decrypted or
decoded is stored in a decipher key table memory 3113. Also, the
bus encrypting and decrypting circuit 3114 receives and
bus-decrypts, for example, the updated and bus-encrypted decipher
key via the interface 3121, the SCSI bus 3152 and the interface
3120 from the bus encryption decipher key table memory 3115, and
stores the bus-decrypted decipher key in the decipher key table
memory 3113. Thereafter, the bus-decrypted decipher key is recorded
on the optical disk 3100 by the recording and reproducing circuit
3119.
[0297] After the decipher key status table is reproduced from the
optical disk 3100 by the recording and reproducing circuit 3119,
the decipher key status table is transferred to and stored in the
decipher key status table memory 3116 via the interface 3120, the
SCSI bus 3152 and the interface 3121. In addition, the decipher key
status table that is updated by the personal computer 3104 is read
out from the decipher key status table memory 3116, and then, is
transferred to the recording and reproducing circuit 3119 via the
interface 3121, the SCSI bus 3152 and the interface 3120.
Thereafter, the recording and reproduced circuit 3119 records the
received decipher key status table on the optical disk 3100.
Accordingly, only the encrypted decipher key is handled on the
personal computer 3104, which is located in the middle, by using
the encryption decipher key table 3115 and the decipher key status
table memory 3116, and this leads to establishment of more
security.
[0298] Carrying out a bus-encryption of the decipher key in the
same way between the optical disk apparatus 3102 and the decoding
apparatus 3103 leads to the establishment of more security. That is
to say, the bus decrypting circuit 3117 of the decoding apparatus
3103 bus-decrypts or bus-decodes the encrypted decipher key that is
received from the personal computer 3104 via the interface 3123,
and stores the bus-decrypted decipher key in the decipher key
memory 3118. The decrypting circuit 3141 decrypts the data of the
encrypted content by using the decipher key that is stored in the
decipher key memory 3118.
[0299] As shown in the above-mentioned seventh preferred
embodiment, in the case where the decipher key for decrypting the
data of the encrypted content on the optical disk 3100 is recorded
in the form of a table, the decipher key table that is reproduced
by the optical disk apparatus 3102 is bus-encrypted by the bus
encrypting and decrypting circuit 3114, and thereafter, the data of
the bus encrypted decipher key table is transferred to the bus
encrypted decipher key table memory 3115 of the personal computer
3104 via the interface 3120, and is stored therein. When the data
of the content is recorded, the personal computer 3104 searches by
retrieving an empty area of the decipher key table from the
decipher key status table recorded in the optical disk 3100 in a
form of plain text, and then, the bus encrypted decipher key that
is transferred from the encoding apparatus 3101 is allocated to the
searched empty area. In this case, when such an encryption is
completed with the decipher key unit as a bus, encryption (for
example, a block encryption with a unit of decipher key length), it
is not necessary to decrypt and re-encrypt the decipher key upon
allocation thereof to the decipher key block.
[0300] Since the decipher key table and the decipher key status
table that are transferred and stored among the optical disk
apparatus 3100, the optical disk apparatus 3102 and the personal
computer 3104 are one piece of block data, respectively, they can
be called a block data.
[0301] In the case when the content is reproduced, only the
decipher key that is required for decrypting the content that is
desired to be reproduced from the decipher key block that was
reproduced from the optical disk apparatus 3102 is retrieved and
taken out from the bus encrypted decipher key table memory 3115,
and the retrieved decipher key is transferred to and stored in the
decipher key memory 3118 via the bus decrypting circuit 3117 of the
personal computer 3104 and the decoding apparatus 3103. Then, the
decrypting circuit 3141 receives encrypted AV data that is
reproduced from the optical disk 3100 by the recording and
reproducing circuit 3119 of the optical disk apparatus 3102 via the
personal computer 3104 and the interface 3123, and thereafter, the
received encrypted AV data is decrypted by using the decipher key
within the decipher key memory 3118, and the decrypted data is
outputted as an image signal and a speech sound signal. In this
case, in a manner similar to that of above-described case, when the
content is recorded, it is not necessary to decrypt and re-encrypt
the decipher key when the decipher key is taken out (retrieved)
from the decipher key block when such an encryption is completed
with a unit, of decipher key as a bus encryption (for example, a
block encryption with a unit of decipher key length). Furthermore,
when the size of the decipher key is enlarged, the expansion of the
decipher key area such as allocating a plurality of decipher keys
can be carried out easily and safely on the personal computer 3104
without changing any configuration of the optical disk apparatus
3102.
Tenth Preferred Embodiment
[0302] FIG. 37 is a block diagram showing a configuration of a user
data area on an optical disk, a configuration of an optical disk
recording apparatus for encrypting content and recording encrypted
content in the user data area, and a configuration of an optical
reproducing apparatus for decrypting an encrypted content from data
in the user data area according to a tenth preferred embodiment of
the present invention. This tenth preferred embodiment is
characterized in that the configuration of the optical disk
recording apparatus is added to that of the sixth preferred
embodiment, and the configuration thereof will be described in
detail.
[0303] In the optical disk recording apparatus, in order to enhance
the intensity of the encryption so as not to have a constant
encryption result, after obtaining or acquiring a content decipher
key by performing a predetermined key conversion on the inputted
cipher key such as multiplication, division or an operation
(calculation), using a predetermined weighting coefficient by the
key converter 2119 using the decipher key conversion data which is
the information in the content, the data of the content is
encrypted by using the content decipher key.
[0304] That is to say, when the content is recorded, the data of
the content and the cipher key for encrypting the data of the
content are inputted to the optical disk recording apparatus. In
this case, the data of the content are inputted to the key
converter 2119 and the encrypting device 2120, and the cipher key
is inputted to the key encrypting device 2118 and the key converter
2119. The key converter 2119 performs an operation or calculation
of a predetermined key conversion on the above-mentioned inputted
cipher key by using the first and the second decipher key
conversion data 2115 and 2116, which are respectively part of the
information in the content, and then, generates and outputs a
content decipher key to the encrypting device 2120. Then, the
encrypting device 2120 encrypts the data of the above-mentioned
inputted content by using the above-mentioned content decipher key,
and then, records the encrypted content in an AV data recording
sector 2152 within the user data area 2150 on the optical disk.
[0305] In this case, since the decipher key conversion data that
are used in the optical disk reproducing apparatus are utilized,
the second decipher key conversion data 2116, which is the
information in the AV data and which is generally different in a
unit of sector, copy generation management information included in
the sector in which control information is recorded, and the first
decipher key conversion data 2115 which is copy control information
including an analog macro-vision control flag. By utilizing the
former second decipher key conversion data, it becomes possible to
recover the content decipher key for encrypting the data of the
content for each sector by the key converter 2113 in accordance
with the content of the second decipher key conversion data. Also,
since the latter first decipher key conversion data is data for
which irregular utilization can be easily detected upon
falsification, such an advantageous effect can be obtained whereby
it can readily be possible to prevent the data of the content from
being decrypted when the first decipher key conversion data is
falsified. More concretely, the cipher key is converted into a
decipher key though a predetermined conversion operation by using
the data in the reproduction control recording sector for recording
reproduction control information that is used for reproduction
control of the AV data as the first decipher key conversion data,
and the converted decipher key is used as a content decipher key in
the encrypting device 2120. In addition, by performing a
predetermined conversion operation or calculation on the cipher key
using the two pieces of decipher key conversion data including the
first decipher key conversion data, which is data in the
reproduction control recording sector, and the second decipher key
conversion data, which is a part of non-encrypted content in the
sector for recording the encrypted content therein, another content
decipher key is calculated which may be used as a content decipher
key in the encrypting device 2120.
[0306] On the other hand, the key encrypting device 2118 encrypts
the above-mentioned inputted cipher key using a disk key that is
inputted in the same way as that of the optical disk reproducing
apparatus, and generates the encrypted decipher key. As compared
with the size of this encrypted decipher key, each of the decipher
key areas 2106 and 2109 in the sector header area is small.
Therefore, the data divider 2121 divides the encrypted decipher key
into a plurality of divided decipher keys, and then, records the
respective divided decipher keys into different decipher key areas
2106 and 2109. In an example of FIG. 37, the encrypted decipher key
is divided into two encrypted divided decipher keys, which are then
recorded in the decipher key areas 2106 and 2109 of two continuous
sectors. In this case, since the decipher key of a cipher key is
encrypted by the key encrypting device 2118, the security intensity
of the encryption for the cipher key can be enhanced.
[0307] When the content is reproduced, the key converter 2113
performs an operation or calculation of a predetermined key
conversion on the decipher key from the key decrypting device 2112
by using information of the above-mentioned first decipher key
conversion data 2115 and the second decipher key conversion data
2116 so as to generate the content decipher key, which is then
outputted to the decrypting device 2114. Also, the decrypting
device 2114 decrypts the data of the encrypted content by using
this content decipher key so as to obtain the decrypted content. In
this case, the key converter 2113 may perform an operation or
calculation of a predetermined key conversion on the decipher key
from the key decrypting device 2112 by using only the information
of the first decipher key conversion data 2115.
Eleventh Preferred Embodiment
[0308] FIG. 38 is a block diagram showing a configuration of a user
data area on an optical disk, a configuration of an optical disk
recording apparatus for encrypting content and recording encrypted
content in the user data area, and a configuration of an optical
disk reproducing apparatus for decrypting an encrypted content from
the data of the user data area according to an eleventh preferred
embodiment of the present invention. This eleventh preferred
embodiment is characterized in that the configuration of the
optical disk recording apparatus is added to optical disk recording
apparatus of the seventh preferred embodiment, and the
configuration thereof will be described in detail.
[0309] Referring to FIG. 38, the optical disk recording apparatus
comprises a key encrypting device 2118 for encrypting a cipher key
by using a predetermined disk key in the same way as that of the
tenth preferred embodiment shown in FIG. 37, a key converter 2119
for operating or calculating a content decipher key through an
operation of a predetermined key conversion on the cipher key by
using the first and the second decipher key conversion data 2115
and 2116 in the content, and an encrypting device 2120 for
encrypting the content using the abovementioned content decipher
key. In this case, the decipher key that is outputted from the key
encrypting device 2118 is recorded in the main data area 2102
within the lead-in area 2401. On the other hand, the optical disk
reproducing apparatus comprises a key decrypting device 2112, a key
converter 2113, and a decrypting device 2114 in the same way as the
optical disk reproducing apparatus of the seventh preferred
embodiment shown in FIG. 29. In this case, the decipher key that is
recorded in the main data area 2102 within the lead-in area 2401 is
read out and is inputted to the key decrypting device 2112, which
then decrypts the decipher key by using a predetermined disk key
and which outputs the decrypted decipher key to the key converter
2113. Also, the key converter 2113 performs an operation or
calculation of a predetermined key conversion on the decipher key
from the key decrypting device 2112 by using the first and the
second decipher key conversion data 2115 and 2116 to calculate the
content decipher key, which is outputted to the decrypting device
2114.
Advantageous Effects of Sixth to Ninth Preferred Embodiments
[0310] As described above, an optical disk of recording type
according to the present preferred embodiments divides and records
the decipher key into decipher keys of the decipher key areas
having a predetermined size arranged in the sector header area, or
records the decipher key having a variable length in the decipher
key area indicated by the key index area arranged in the sector
header area, and then, an optical disk of recording type which can
utilize a decipher key of an arbitrary or free length regardless of
a decipher key area of a size prescribed in the sector header area
can be provided. Therefore, in accordance with the copyright
protection level for the recorded content, it becomes possible to
utilize the encryption using an arbitrary key length.
Modified Preferred Embodiments
[0311] In the above-mentioned preferred embodiments, the
above-mentioned disk identification information is preferably
constituted by pre-pits which are non-rewritable, and the
above-mentioned disk identification information has has a region
identifier for representing a region in which the optical disk is
used. Also, the above-mentioned disk identification information
preferably has a data category identifier representing a type,
class or kind of content which is recordable and reproducible on
the optical disk. In addition, the above-mentioned disk
identification information is, preferably, encrypted by using a
secret key, and recorded in the disk identification information
area upon manufacturing. Furthermore, the above-mentioned disk
identification information preferably includes data for
representing a type, class or kind of data which is recordable in
the data recording and reproducing areas, or a type, class or kind
of data which is reproducible from the data recording and
reproducing area.
[0312] In the above-mentioned preferred embodiments, the
above-mentioned optical disks preferably have a sector area for
data of the content therein, and a descramble area management table
for managing the corresponding relationship with the descramble
key. The key management information area preferably includes a
descramble key area for recording a descramble key encrypted using
disk identification information as a key, a key information area
having a descramble key status area for representing a recording
status or state of the descramble key, a content information area
for recording therein key information that is used upon the
reproduction of the content that is recorded on the disk, and a key
index area for recording therein a pointer for referring to a
descramble key that is required for the reproduction of the
content. In addition, in the sector recording the data of the
content, there are preferably recorded the data of the
above-mentioned content, and a pointer for indicating an area for
recording the descramble key therein.
[0313] In the above-mentioned preferred embodiments, a reproducing
circuit of the disk identification information of the optical disk
recording and reproducing apparatus preferably comprises a circuit
for decrypting disk identification information which has been
encrypted by using a secret key. Also, in the optical disk
recording and reproducing apparatus, the data that are encrypted
with the disk identification information as a key are preferably
data of content such as image data and music data. In addition, the
disk identification information preferably represents a type, class
or kind of data which is recordable in the data recording and
reproducing area, and the reproducing circuit of the disk
identification information determines whether or not the data is of
recordable content by the type, class or kind of the
above-mentioned data. Furthermore, the data which is decrypted by
using the disk identification information as a key is preferably
data of the content such as image data or music data. Also, the
disk identification information preferably represents a type, class
or kind of data which is reproducible from the data recording and
reproducing area, and the reproducing circuit determines whether or
not the data is of reproducible content based on the type, class or
kind of the above-mentioned data.
[0314] In the above-mentioned preferred embodiments, the recording
circuit of the content preferably records data of content such as
encrypted image data and music data and the descramble key for
decoding or decrypting encryption of the data of the
above-mentioned content, in the same sector. Also, the reproducing
circuit of the content preferably reproduces data of content such
as encrypted image data and music data and the descramble key for
decoding or decrypting encryption of the data of the
above-mentioned content from the same sector.
[0315] In the above-mentioned preferred embodiments, a circuit or a
method for allocating key areas preferably arranges a flag for
reserved area in a descramble key status area for representing a
recorded status of the descramble key, records information with
respect to a key used upon reproduction of the data of the content,
and records a key index for representing a recording area of the
descramble key allocated for the data of the content. Also, a
circuit or a method for arranging the descramble key preferably
reproduces an index of a descramble key area used in the content
from the content information area, arrange a descramble key into a
descramble key area indicated in a key index corresponding to the
recorded descramble key, and arrange a flag of recorded information
in a descramble key status area indicated in the key index
corresponding to the recorded descramble key.
[0316] In the above-mentioned preferred embodiments, the optical
disk reproducing apparatus preferably reproduces disk
identification information, searches whether or not content is
reproducible, reproduces key management information, reproduces a
sector in which data of content such as image data or music data
have been recorded, and acquires a descramble key from the
reproduced sector. In addition, the data of the reproduced content
is preferably descrambled by the descramble key, and the
descrambled data is outputted.
[0317] In the above-mentioned preferred embodiments, the method for
recording data of content preferably records encrypted content so
as to be able to be decoded and reproduced through an operation or
calculation using at least the above-mentioned second disk
information, when the content is recorded in the user data area of
an optical disk having a first information area for recording first
disk information therein, a second information area for recording
therein second disk information for identifying individual disks
and the user data area for recording information by irradiating a
light beam onto the user data area.
[0318] In the above-mentioned preferred embodiments, the method for
recording data of content is preferably to encrypt and record
information so as to be decoded and reproduced by an operation or
calculation using at least the second disk information and the key
information, when recording the content in the above-mentioned user
data area of the optical disk having a first information area for
recording first disk information therein, a second information area
for recording therein second disk information for identifying
individual disks, a user data area for recording information by
irradiating a light beam onto the user data area, and a key
information recording area for recording key information for
decoding or decrypting content that are encrypted and recorded
within the user data area.
[0319] In the above-mentioned preferred embodiments, dummy data is
recorded in a sector of an optical disk having a decipher key area
for recording a plurality of divided decipher keys in a plurality
of continuous sectors, preferably in the main data area in which a
data size including the AV data is less than (main data size) x
(number of divided decipher keys). Also, in the ECC block, the
sector having a decipher key area for recording divided decipher
keys that are divided into a plurality of continuous sectors is
recorded (ECC block unit)/(number of divided decipher keys) times,
and the dummy data is recorded in the main data area in which the
data size including the AV data is less than (main data size) x
(ECC block unit).
[0320] In the above-mentioned preferred embodiments, a decipher key
for decrypting encryption which has been performed on data
including the AV data is preferably divided into a plurality of
divided decipher keys with a predetermined size, and the plurality
of divided decipher keys are recorded in a plurality of decipher
key areas in which the decipher key table continues. Also, the
above-mentioned decipher key table is preferably recorded in the
main data area within the rewritable lead-in area. In addition,
information for representing the recording status or state of the
decipher key table is preferably recorded in each decipher key area
of the decipher key table as a fixed value. Furthermore, the
decipher key table is recorded a plurality of times in the
above-mentioned different ECC blocks that are arranged in the inner
and the outer peripheries of the optical disk.
[0321] In the above-mentioned preferred embodiments, the encoding
apparatus 3101 of a data encrypting apparatus, and the optical disk
apparatus 3102 of an optical disk recording and reproducing
apparatus, preferably share the bus key in a mutual authorization
system. Also, the decoding apparatus 3103 of a data decoding
apparatus, and an optical disk apparatus 3102 of an optical disk
recording and reproducing apparatus preferably share the bus key in
a cross authenticating system.
[0322] Although, in the above-mentioned preferred embodiment, an
optical disk of recording type which can record data, and which is
either write-once type or rewritable type including a RAM type or
non-rewritable optical disk, is described, the present invention is
not limited thereto. The present invention can be applied for a
read-only type optical disk which can read out and reproduce the
previously recorded data but which cannot newly record data. In the
case of the read-only type optical disk, the data recording and
reproducing area can be replaced with the data reproducing area
which reads out and reproduces the data, and the data of the
content or the data of other various control information is
previously recorded upon manufacturing. In this case, the recording
type optical disk includes CD-R, CD-RW, MO, MD, DVD-RAM and so
forth. The read-only type optical disk includes music CD, CD-ROM,
DVD-ROM and so forth.
ADVANTAGEOUS EFFECTS OF THE INVENTION
[0323] As described above in detail, according to an optical disk
of the present invention, disk identification information using
which recording operation and reproducing operation are performed
for each optical disk is recorded in a produce-only area which is
non-rewritable, and the recording operation and the reproduction
operation of the content onto or from the optical disk can be
controlled by the user by utilizing the information that is
recorded upon the manufacture of the optical disk.
[0324] Also, according to an optical disk of the present invention,
data, which has been encrypted by using the read-only disk
identification information which is impossible to be rewritten, as
a key, is recorded in the user data area of the optical disk.
Therefore, even in the case where the user data area is copied onto
another optical disk of recording type by the user, the disk
identification information cannot be copied so that correct
decryption and reproduction of the data becomes impossible.
[0325] In addition, according to an optical disk of the present
invention, encrypted data and a descramble key for decrypting
encryption are recorded in sector areas which are different from
each other, and it becomes possible to acquire data such as movies
and music required for copyright protection and to acquire a
descramble key for descrambling encryption independently. Moreover,
by encrypting and recording the descramble key by using the disk
identification information as a key, the disk identification
information cannot be copied, which makes it impossible to
correctly record and reproduce the data even if the user data area
is copied onto another optical disk of recording type by the user.
By acquiring and recording the descramble key which has been
encrypted by using the disk identification information of the
optical disk onto which the data are copied as a key, this makes it
possible to correctly record and reproduce the data.
[0326] Moreover, an optical disk according to the present invention
comprises a first information area for recording a first disk
information therein, a second information area for recording a
second disk information for identifying individual disks, and a
user data area for recording information by irradiating a light
beam onto the user data area. Accordingly, by adding information
for identifying the above-mentioned optical disk to an optical disk
according to the prior art, the management of optical disks can
easily be implemented. In this case, the above-mentioned second
information area is preferably recorded in the above-mentioned
first information area, and data of the second information area can
be reproduced by an optical pick up for reproducing the
above-mentioned first information area. Also, the above-mentioned
second information area is recorded by partially eliminating or
removing a recording film within the above-mentioned first
information area, so that a plurality of trimming areas having an
elongated shape in the radius direction are formed, and therefore,
easy falsification of the above-mentioned second disk information
can be prevented.
[0327] In addition, according to an optical disk of the present
invention, a decipher key is divided into a plurality of divided
decipher keys which are then allocated in decipher key areas each
having a predetermined size arranged in the sector header area, or
a decipher key is recorded in the decipher key areas indicated by
an key index area arranged in the sector header area. Accordingly,
an optical disk of recording type can be provided which can utilize
the decipher key having an arbitrary or free length, independently
of the decipher key area having a prescribed size in the sector
header area. Therefore, it becomes possible to use an encryption
using an arbitrary key length in accordance with the level of
copyright protection level for recorded content.
[0328] Although the present invention has been fully described in
connection with the preferred embodiments thereof with reference to
the accompanying drawings, it is to be noted that various changes
and modifications will be apparent to those skilled in the art.
Such changes and modifications are to be understood as being
included within the scope of the present invention as defined by
the appended claims unless they depart therefrom.
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