U.S. patent application number 14/668531 was filed with the patent office on 2015-08-06 for method and apparatus for making a decision on a card.
The applicant listed for this patent is Assa Abloy AB. Invention is credited to Michael L. Davis, Tam Hulusi, Robert Wamsley.
Application Number | 20150220722 14/668531 |
Document ID | / |
Family ID | 38649925 |
Filed Date | 2015-08-06 |
United States Patent
Application |
20150220722 |
Kind Code |
A1 |
Davis; Michael L. ; et
al. |
August 6, 2015 |
METHOD AND APPARATUS FOR MAKING A DECISION ON A CARD
Abstract
Method and devices for making access decisions in a secure
access network are provided. The access decisions are made by a
portable credential using data and algorithms stored on the
credential. Since access decisions are made by the portable
credential non-networked hosts or local hosts can be employed that
do not necessarily need to be connected to a central access
controller or database thereby reducing the cost of building and
maintaining the secure access network.
Inventors: |
Davis; Michael L.; (Austin,
TX) ; Wamsley; Robert; (Golden, CO) ; Hulusi;
Tam; (Santa Ana, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Assa Abloy AB |
Stockholm |
|
SE |
|
|
Family ID: |
38649925 |
Appl. No.: |
14/668531 |
Filed: |
March 25, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14017065 |
Sep 3, 2013 |
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14668531 |
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13274863 |
Oct 17, 2011 |
8578472 |
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14017065 |
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11778145 |
Jul 16, 2007 |
8074271 |
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13274863 |
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60821897 |
Aug 9, 2006 |
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Current U.S.
Class: |
726/20 |
Current CPC
Class: |
G07C 9/29 20200101; G07C
2209/08 20130101; G07C 9/23 20200101; H04L 63/08 20130101; G06F
21/35 20130101; G07C 9/257 20200101; G06F 21/00 20130101; G06F
21/34 20130101; G06F 21/31 20130101; H04L 63/101 20130101 |
International
Class: |
G06F 21/35 20060101
G06F021/35 |
Claims
1. A method, comprising: performing a mutual authentication between
a reader and a credential; following the mutual authentication,
enabling the reader to communicate status information along with a
reader identifier to the credential; communicating the reader
identifier along with the status information from the credential to
a server thereby enabling the server to determine a location of the
credential based, at least in part, on the reader identifier.
2. The method of claim 1, wherein the status and reader identifier
of the reader are communicated via TCP/IP.
3. The method of claim 1, wherein the status includes a locked or
unlocked status of the reader.
4. The method of claim 1, the status information includes a
timestamp corresponding to a time when the reader and credential
mutually authenticated with one another.
5. The method of claim 1, wherein the status of the reader is
communicated to the credential directly via a Radio Frequency (RF)
antenna.
6. The method of claim 1, further comprising: enabling the
credential to use the reader identifier to make an access control
decision for itself; and communicating results of the access
control decision from the credential to the reader.
7. The method of claim 1, wherein the reader identifier is
communicated to the server via a mobile communication network.
8. The method of claim 1, wherein the credential comprises a
cellular phone.
9. The method of claim 1, wherein the reader comprises a
stand-alone reader.
10. The method of claim 9, further comprising: implementing an
action at the reader consistent with the results of the access
control decision made at the credential.
11. A system, comprising: a reader comprising a credential
interface; and a credential comprising a reader interface thereby
enabling the reader and credential to communicate with one another
and perform mutual authentication after which the reader is
configured to communicate status information along with a reader
identifier to the credential such that the credential is able to
determine a location for itself based, at least in part, on the
received reader identifier.
12. The system of claim 11, wherein the credential is further
configured to communicate the reader identifier and status
information to a server thereby enabling the server to determine a
location of the credential based, at least in part, on the reader
identifier.
13. The system of claim 12, wherein the reader identifier is
communicated to the server via a cellular network.
14. The system of claim 12, wherein the status and reader
identifier are communicated via TCP/IP.
15. The system of claim 11, wherein the status includes a locked or
unlocked status of the reader.
16. The system of claim 11, wherein the status of the reader is
communicated to the credential directly via a Radio Frequency (RF)
antenna.
17. The system of claim 11, wherein the credential comprises a
cellular phone.
18. The system of claim 11, wherein the reader comprises a
stand-alone reader.
19. The system of claim 11, wherein the status information includes
a timestamp corresponding to a time when the reader and credential
communicated with one another.
20. The system of claim 11, wherein the credential is further
configured to make an access control decision for itself based, at
least in part, on the reader identifier.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 14/017,065, filed Sep. 3, 2013, which is a
continuation of U.S. patent application Ser. No. 13/274,863, filed
Oct. 17, 2011, now U.S. Pat. No. 8,578,472, which is a continuation
of U.S. patent application Ser. No. 11/778,145, filed Jul. 16,
2007, now U.S. Pat. No. 8,074,271, which claims the benefit of U.S.
Provisional Application No. 60/821,897, filed Aug. 9, 2006, the
entire disclosures of which are hereby incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to access control
systems, devices, and methods. More specifically, the present
invention provides an access control system in which authentication
decisions are made on a credential.
BACKGROUND
[0003] In prior art access control systems, for example as shown in
FIG. 1, typically credentials 120 (or other equivalent tokens) are
used to authenticate a user to a system. These systems often employ
cryptographic protocols, such as ISO 9798-2, to effect mutual
authentication between the system and the card. Access is granted
when the system recognizes the user, finds the privileges for the
user in a database, and makes the decision based on the user's
privileges outlined in the database. In all these prior art systems
the credential 120 is primarily an information carrier; little use
is made of processing power inherent in the credential 120.
[0004] In many prior art systems, the database is centralized. FIG.
1 depicts a centralized access control system 100 with a
centralized database 104. The benefit of a centralized database in
access control is the ease of data management, speed, and
consistency with which data updates are shared in the access
control system 100. However, such prior art systems suffer from
high installation costs. If the access control decision is made
centrally, then the locks and/or access points 108 are networked
(either wired or wirelessly) to a central server or control panel
112. This is expensive. In the case of wired networks, there are
costs associated with materials and labor because the wiring must
be physically installed between all system components. In the case
of wireless networks, there are increased costs associated with
ensuring reliable and secure communication between all network
nodes.
[0005] Another drawback of these prior art systems is their
reliance on a physically or wirelessly connected network 116. Such
reliance can cause service interruptions when the network is not
available. Prior art systems typically do not store policy
information (i.e., information used to grant or deny access to a
credential 120) at access points such as a door. Instead the system
operates in reduced-mode when communication is lost. Storing policy
information at the door is possible in prior art systems, but at a
higher cost due to both equipment and maintenance.
[0006] Other prior art systems, such as those found in WO04025545
and U.S. Pat. No. 6,719,200 make authentication checks based on
biometric information using a networked connection and a credential
120 or other processor device. In these types of prior art systems,
a biometric template is stored on the credential 120 and a second
biometric template is created from a biometric scan taken in
response to an access request. The second biometric template is
stored in a database 104 on the network 116 and sent to the
credential 120 upon presentation of the credential 120 to an access
reader. These systems use biometrics for authentication that can
later lead to a control decision after user rights are checked, but
the credential's processor does not make the access control
decision. Rather, the credential's processor verifies that the
biometric data received from the network database matches biometric
data stored on the credential 120 before any further communications
are initiated by the credential with a reader for purposes of
gaining access. In these systems the reader still makes the
ultimate access control decision.
[0007] In other prior art systems, policy information from the
database 104 is distributed among non-networked locks. In these
prior-art systems, the management of the policy information is
problematic. Updating the databases may be accomplished by special
reprogramming visits by security personnel, but this is expensive
in time, especially in a large system having numerous non-networked
locks. Alternatively, the lock database is updated via a
pseudo-network created on the user cards, such as the one discussed
in WO05024549A2. In these systems, datagram networking techniques
pass database records from central system to non-networked locks by
additional messaging between user card and lock, see for example
U.S. Pat. No. 6,766,450. Typically, systems based on this model
involve passing a large amount of data between the user card and
the lock, which slows the access control process and makes the
experience unpleasant for the user, and consumes energy. This can
be a serious detriment in the case of battery-powered locks where
power consumption is at a premium.
[0008] In yet other prior art systems, such as those described in
U.S. Pat. No. 6,374,356, the database of policy information for
each user is carried on the card itself. For example, if a user is
privileged to open a certain subset of doors in the system, then
the card holds information to that effect. In these prior art
systems, the lock reads the database record from the card, then the
lock determines if the user privileges include opening the lock. In
large systems, the access control database record may contain a
relatively large amount of data that must be passed to the lock.
This transfer of data again slows the access control process and
consumes energy.
[0009] Database management and transmitted policy information
described in the prior art are both processes that can consume
significant amounts of time and energy. Energy use is an important
consideration for applications where the local door device is
battery operated.
SUMMARY
[0010] In one embodiment, the problem associated with updating
disconnected readers is addressed by obviating the need for policy
information to be transferred from the credential to the reader. In
accordance with at least one embodiment of this invention, the
credential holds policy information and the local host transfers
information needed to make an access decision to the credential.
The credential uses its processor to make the enforcement decision
and transfers the decision or results of that decision to the local
host.
[0011] While embodiments of the invention do not preclude the
capability of transmitting identity information from the credential
to the reader, some embodiments may provide the additional
capability of securely enforcing control policy without disclosing
the credential identity. Moreover, embodiments of the present
invention can be used with a networked control system or in a
distributed control system. Additionally, certain embodiments of
the invention offer a cost saving means by making it possible to
create an access control system that is expandable with
non-networked readers.
[0012] It is one objective of the present invention to provide a
secure access control system capable of working with non-networked
hosts (local hosts), in which a reader of the local host contains
no database, and in which a minimal amount of communication is
required between the local host and the credential.
[0013] Aspects of the invention address technical problems inherent
in prior art systems by having the policy information or user
privilege data on the credential and the access control decision
made using the credential's microprocessor and communicated to an
access control device associated with the local host.
[0014] In one embodiment, a local host need only authenticate with
the credential using an appropriate protocol, which are well known
in the prior art, and transmit to the credential an ID and/or
functional identification. After mutual authentication, time and
date information are passed from the local host to the credential.
This represents a relatively small amount of data and is virtually
independent of system size. It should be noted that scalability of
the system may depend on additional required messaging, such as a
Certificate Revocation List (CRL). As can be appreciated by one of
skill in the art, CRLs present just one way to invalidate a user. A
CRL can be used if the credential information is digitally signed.
More generally, however, a list of revoked credentials may be
employed.
[0015] According to one embodiment of the present invention, each
credential carries unique privilege information for the credential
user, which may include a list of local host or door ID numbers,
timestamps, access schedule information, security class
information, and additional rules or controls relevant to the
user's access authorizations. This information might be coded as a
list of door ID numbers, or as a set of rules, or in other ways
which are well known to those skilled in the art.
[0016] In one embodiment, the processor on the credential runs an
algorithm, contained on the credential, to determine if the
credential holder privileges allow the credential user to open the
door or access the asset protected by the local host. If the
decision is made that the credential user is granted access, then a
secure message is sent to the door or local host requesting the
access control device (e.g., a lock) to open.
[0017] If the processor on the credential determines that the
credential user is not allowed access to the asset, then no further
action is required. Alternatively, if a no-access decision by the
credential is made, the credential may send a code to the reader,
which allows both the reader and credential to record an
unauthorized attempt to gain access. The record may be stored at
the reader, the credential, or both. This type of information
related to an unauthorized access attempt might be useful for later
investigation or security analysis.
[0018] It is assumed that privileges and algorithms residing on the
credential can be periodically and securely maintained by
appropriate means, such as connection to or communication with a
central database by a credential reader/writer. The reader/writer
may be associated with a PC, workstation, or at a networked
access-control point. This is preferable of prior art schemes where
a database is updated periodically on the reader, because the
reader is typically stationary and may be remote, whereas the
credential is mobile and typically carried by the user wherever he
might require to use it. The credential can therefore be brought to
the reader/writer rather than bringing the reader/writer to all
local hosts.
[0019] Expiration of the privileges on the credential (e.g., to
prevent unauthorized use of a lost or misplaced credential) may be
enforced by time-stamping the privileges on the credential, or by
other known mechanisms. In any case, the processor on the
credential may still make the access control decision by running an
algorithm.
[0020] In one embodiment, the access control system comprises one
or more non-networked door locks otherwise known as local hosts,
one or more credentials, one or more credential reader/writers, and
a central access control system including a master database and
system administrator interface.
[0021] The local host, in one embodiment, comprises an access
control device and a controller. The controller preferably utilizes
a microprocessor, a random number generator or alternatively a
secure seed and a pseudo-random number generator, a cryptographic
coprocessor, and control circuitry to operate the blocking
mechanism (e.g., a lock, password protection program, or the like).
The local host may further include a power source such as a battery
or a solar cell, volatile and nonvolatile memory, a real-time
clock, and a Radio Frequency Identification (RFID) reader or other
communication mechanism.
[0022] The credential, in one embodiment, comprises a communication
mechanism, for example, either an RFID antenna or electrical
contacts typical to a contact credential 216, and a smartcard
controller. The credential 216 controller generally comprises a
microprocessor, RFID or other communications circuitry, a random
number generator, a cryptographic coprocessor, and volatile and
non-volatile memory. Preferably the memory and circuitry of the
credential and the local host are designed utilizing security
features to prevent unauthorized access to the memory contents,
side channel analysis, and the like.
[0023] In a transaction, the reader of the local host supplies its
ID and current date and time information to the credential. The
credential contains access privilege data, normally specific to the
credential holder. Based on the ID and time, coupled with the
privileges data, the credential decides if the credential holder
may access the asset protected by the local host.
[0024] In one embodiment, if access is granted, then the credential
issues a secure "unlock request" to the local host. If access is
not granted, then no action need be performed. As can be
appreciated, a system based on embodiments of this invention can be
made secure against playback and other simple attacks by employing
suitable cryptographic techniques in authentication and
messaging.
[0025] The Summary is neither intended or should it be construed as
being representative of the full extent and scope of the present
invention. The present invention is set forth in various levels of
detail and the Summary as well as in the attached drawings and in
the detailed description of the invention and no limitation as to
the scope of the present invention is intended by either the
inclusion or non inclusion of elements, components, etc. in the
Summary. Additional aspects of the present invention will become
more readily apparent from the detailed description, particularly
when taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 depicts a centralized access control system in
accordance with
[0027] embodiments of the prior art;
[0028] FIG. 2 depicts an access control system in accordance with
embodiments of the
[0029] present invention;
[0030] FIG. 3 depicts components of a local host in accordance with
embodiments of the present invention;
[0031] FIG. 4 depicts components of a credential in accordance with
embodiments of the present invention;
[0032] FIG. 5 depicts logical data components of the access control
system in accordance with embodiments of the present invention;
[0033] FIG. 6 depicts a method of initializing a credential with
access data in accordance with embodiments of the present
invention;
[0034] FIG. 7 depicts a method of refreshing access information on
a credential in accordance with embodiments of the present
invention;
[0035] FIG. 8 depicts a method of operating a local host in
accordance with embodiments of the present invention; and
[0036] FIG. 9 depicts a method of authenticating a credential with
local host in accordance with embodiments of the present
invention.
DETAILED DESCRIPTION
[0037] Embodiments of the present invention are directed toward
devices and methods of using such devices in a secure access
system. Although well suited for use in systems and methods
employing RF communication protocols, embodiments of the present
invention may be suitable for use in systems employing other
communication protocols including, but not limited to, optical
communication protocols, magnetic communication protocols, and the
like.
[0038] FIG. 2 depicts a secure access system 200 in accordance with
at least some embodiments of the present invention. The secure
access system 200 generally includes a privilege server 204 and a
validation server 208 that communicate with one or more credentials
216 through a reader/writer 212. The privilege server 204 and
validation server 208 are dedicated servers that provide certain
services to credentials 216 in the system 200. Although depicted
separately, a single server or similar device may execute the
functionality of both the privilege server 204 and the validation
server 208. The privilege server 204 and/or validation server 208
are capable of communicating with the reader/writer 212 via any
known communication protocol such as Internet Protocol (IP)
standard or the like.
[0039] The privilege server 204 initializes, modifies, and changes
applications and application data stored on a credential 216 by
using the writing feature of the reader/writer 212. The privilege
server 204 can increase or decrease the scope of the privileges
associated with the credential. The privilege server 204 has access
to a user database that identifies what access permissions various
users in the system 200 have. When a credential 216 is presented to
the reader/writer 212, the privilege server 204 accesses data on
the credential 216 using a symmetric key, Kp, that is shared
between the privilege server 204 and the credential 216. Of course,
the key, Kp, may also be an asymmetric key or other type of secret.
Then the privilege server 204 can identify who the holder of the
credential 216 is or is supposed to be. Once the privilege server
204 knows the identity of the holder it can generate the
appropriate access permissions and write those permissions to the
credential 216 in the form of application data. Additionally, the
privilege server 204 can write an application to the credential 216
that is used by the credential 216 to make access decisions based,
in part, on the application data. The privilege server 204 stores
application data that includes, but is not limited to, schedule
data (i.e., access permissions data by time), local host data
(i.e., access permissions by local host), timestamp data, and
authentication keys for each credential 216 in the population of
credentials 216 in the access control system 200. The application
data for each credential 216 may be stored in a portion of memory
in the privilege server 204 or in a separate database. The
privilege server 204 also has access to the current time either by
an Internet connection, an internal clock, or by some other
mechanism.
[0040] The validation server 208 is provided to refresh the
application on a credential 216 with a privilege expiration,
typically in the form of a timestamp. The validation server 208
does not increase the scope of the privileges associated with a
credential, other than by extending the time existing credentials
are valid. The validation server 208 has access to the current
time. The validation server 208 also has access to the current
validation status of all access control privileges for every
credential holder. Validation status information may be stored
either in memory of the validation server 208 or in an external
database. When a credential 216 is presented to the reader/writer
212, the validation server 208 determines if the credential's
status is still active and also determines if the schedule data on
the credential 216 is current. If both are true, then the
validation server 208 sets a new expiration for the application
data on the credential 216. Of course, the validation server 208
does not have to set a new expiration if current data is not
expired. Otherwise, the application data is left alone such that it
either remains expired or will expire after a predetermined
expiration period, or may renew it, even if expired if such
instructions are in the system.
[0041] The reader/writer 212 acts as a communication conduit
between the credential 216, privilege server 204, and validation
server 208. As can be appreciated, a separate and dedicated
reader/writer 212 may be provided for both the privilege server 204
and the validation server 208. Additionally, the reader/writer 212
may also be a networked reader/writer 212 associated with an access
point in the access control system 200. A networked reader/writer
212 may read and perform authentication with the credential 216 and
then act as a communication conduit between the credential 216 and
the validation server 208. The system may also be a single server
with both the privilege and validation functionality working
through a single reader/writer. There may also be multiple
reader/writers connected in a network at different locations to
permit credentials to be updated or validated at physically
different locations but under the control of a single
administrative system.
[0042] The credential 216 may be any suitable type of access
control device. In one embodiment, the credential 216 is capable of
making real-time or near real-time access decisions. In other
words, the credential 216 is capable of determining whether it is
granted or denied access to various assets in the secure access
system 200. The credential 216 stores application data that
includes access permissions and algorithms for making access
decisions. The credential 216 may be provided with a unique ID that
distinguishes it over other credentials 216 in the population of
credentials 216. In one embodiment, the credential ID, application
data, and other data stored on the credential 216 is protected
using various symmetric keys. The credential 216 generally includes
an RF transponder that enables the credential 216 to communicate
using contactless communication protocols. Examples of a suitable
credential 216 include, but are not limited to, a contactless
smartcard, a passport, a key fob, a cellular phone, a PDA, portable
computer, or any other device having appropriate functionality.
Alternatively, the credential 216 may be in some other
machine-readable form. For example, the credential 216 may employ
magnetic, optical, or contact communication methods.
[0043] Using any type of communication protocol, the credential 216
is capable of communicating with a local host 220a-N. A local host
220 is any type of non-networked access point. The local host 220
controls access to one or more assets such as a building, room,
computer, database, file, and so on. The local host 220 is
typically assigned a unique ID that identifies the host or the
asset protected by the host. In one embodiment, the host ID is
passed to the credential 216 in order for the credential 216 to
have enough information to make an access decision. In a preferred
embodiment, the local host 220 only needs to supply its host ID and
the current time to the credential 216.
[0044] Referring now to FIG. 3, an exemplary reader/writer 212 or
local host 220 will be described in accordance with at least some
embodiments of the present invention. The reader/writer 212 or
local host 220 generally comprises a reader 304 capable of
automatically reading data from a credential 216. The reader 304
may also be capable of writing data back to the credential 216. The
reader 304, in one embodiment, comprises an RF antenna used to
communicate back and forth with the credential 216.
[0045] Connected to the reader 304 is a controller 308. In one
embodiment, the controller 308 includes a microprocessor, a random
number generator, and a cryptographic coprocessor. The controller
308 is capable of properly modulating/demodulating data sent to and
received from external devices such as the credential 216. The
controller 308 controls and determines how the reader/writer 212 or
local host 220 behaves when a credential 216 is presented to it.
The controller 308 may include any general-purpose programmable
processor, digital signal processor (DSP) or controller for
executing application programming. Alternatively, the controller
308 may comprise a specially configured application specific
integrated circuit (ASIC).
[0046] The controller 308 may also be provided with control
circuitry capable of manipulating an access control device 312. The
access control device 312 is designed to secure the asset being
protected by the reader/writer 212 or local host 220. Examples of a
typical access control device 312 include, without limitation, an
electronic lock, a magnetic lock, or an electric strike for a door,
a lock for a computer system, a lock for a database, a lock on a
financial account, or a lock on a computer application. In one
embodiment, the controller 308 actuates the access control device
312 based on results of an access decision provided to the
controller 308 from the credential 216. The access control device
312 may be integral to the reader/writer 212 or local host 220 in
one embodiment. In an alternative embodiment, access control device
312 is external to the reader/writer 212 or local host 220.
[0047] In addition to an access control device 312, the
reader/writer 212 or local host 220 may further comprise a memory
316. The memory 316 may be used to store application data, the host
unique ID, and any other functions that can be executed by the
controller 308. The memory 316 may comprise volatile and/or
non-volatile memory. Examples of non-volatile memory include Read
Only Memory (ROM), Erasable Programmable ROM (EPROM),
Electronically Erasable PROM (EEPROM), Flash memory, and the like.
Examples of volatile memory include Random Access Memory (RAM),
Dynamic RAM (DRAM), Static RAM (SRAM), or buffer memory. In one
embodiment, the memory 316 and the controller 308 is designed to
utilize known security features to prevent unauthorized access to
the contents of the memory 316 such as side channel analysis and
the like.
[0048] The reader/writer 212 or local host 220 may further comprise
a clock 320. The clock 320 is depicted as internal to the
reader/writer 212 or local host 220, but the clock may also be
external to the reader/writer 212 or local host 220. The clock 320
tracks the current time. The controller 308 can read the time from
the clock 320 and provide that time to a credential 216. The
credential 216 uses the time from the clock 320 to determine if the
holder of the credential 216 is currently allowed access to an
asset protected by the access control device 312.
[0049] A power source 324 may also be included in the reader/writer
212 or local host 220 to provide power to the various devices
contained within the reader/writer 212 or local host 220. The power
source 324 may comprise internal batteries and/or an AC-DC
converter such as a switch mode power supply or voltage regulator
connected to an external AC power source.
[0050] Although not depicted, a reader/writer 212 may further
include a communication interface that provides communication
capabilities between the reader/writer 212 and external servers or
other network nodes. Such a communication interface may include a
USB port, a modem, a network adapter such as an Ethernet card, or
any other communication adapter known in the art.
[0051] Referring now to FIG. 4, an exemplary credential 216 will be
described in accordance with at least some embodiments of the
present invention. The credential 216 may include a communication
interface 404 that allows the credential 216 to communicate with
external devices such as the reader/writer 212 or local host 220.
The communication interface 404 may comprise an RF antenna that
allows the credential 216 to receive and transmit data without
contact. In other embodiments a magnetic, optical, or electrical
contact communication interface 404 may be utilized.
[0052] A controller 408 may be connected to the communication
interface 404. The controller 404, in one embodiment, includes a
microprocessor, a random number generator, and a cryptographic
coprocessor. The controller 408 may include any general-purpose
programmable processor, digital signal processor (DSP) or
controller for executing application programming. Alternatively,
the controller 408 may comprise a specially configured application
specific integrated circuit (ASIC). Similar to the controller 308
on the reader/writer 212 or local host 220, the controller 408
includes known security features that substantially prevent
unauthorized access to the contents of memory 412.
[0053] The memory 412 typically comprises non-volatile memory, such
as flash memory. Non-volatile memory is generally used because the
credential 216 is preferably a passive credential meaning that it
does not have an internal source of power. Rather, the credential
216 uses energy from an RF field created by the reader/writer 212
or local host 220 to power its components. Contents of the memory
412 may include an access decision application 416. As noted above,
the privilege server 204 may write the access decision application
416 along with application data to the credential 216. In a
preferred embodiment, the access decision application 416 and
application data are written to the credential 216 in a secure
environment. The access decision application 416 contains an
algorithm or algorithms that can be used to make an access
decision. The controller 408 can access the access decision
application 416 and application data to make an access decision
with respect to a particular reader/writer 212 or local host
220.
[0054] In an alternative embodiment the credential 216 may be
provided with an onboard power supply. Such credentials 216 are
known as active credentials 216. An active credential 216 can keep
its own trusted time that can be synchronized with the network
devices during interactions with the privilege server 204 and/or
validation server 208.
[0055] FIG. 5 depicts logical components of each device in the
secure access system 200 in accordance with at least some
embodiments of the present invention. The memory 412 of the
credential 216 generally contains application data and an access
decision application 416. The memory 412 may also include
credential specific data such as a credential ID 504 and a
privilege key Kp 508. The memory 412 may also include an operating
system 512 that defines the normal functionality of the credential
216.
[0056] The access decision application 416 is a second program or
algorithm that may be stored on the memory 412. The access decision
application 416 may be given a unique Application ID 516 that
distinguishes this application from other applications, such as the
operating system 512, that are stored in memory 412. A symmetric
application key Ka 520 is also stored in memory 412. The
application key Ka protects access to the application data. The
application key Ka may be shared upon initialization of the system
or creation of the application with the validation server 208. The
application key Ka 520 is typically different from the privilege
key Kp used by the privilege server 204 to access and rewrite the
entire access decision application 416. The application key Ka 520
is required to update or modify the expiration of the access
decision application 416. Also stored in the memory 412 in
association with the access decision application is a user ID 524.
The user ID 524 identifies the intended user of the credential 216.
The user ID 524 may be an arbitrary identifier such as a randomly
assigned number or may be the user's social security number,
employee number, or the like. The user of the credential 216 is
assigned the user ID 524 for use with the access decision
application 416. The user ID 524 is employed by the privilege
server 204 to assign user access permissions and by the validation
server 208 to update access permissions. The user ID 524 is
generally not needed for use with a local host 220.
[0057] As previously noted, application data may be stored as a
part of the access decision application 416. A set of application
data is substantially unique to a particular application and
therefore is substantially unique to certain local hosts 220. For
example, a first set of application data may be used to make access
decisions for rooms in a building. A second set of application data
may be used to make access decisions for a garage door or the like
whereas a third set of application data may be used to make access
decisions related to electronic files or programs.
[0058] In one embodiment, a first set of application data includes
a control key KD1 528, a control or access schedule 532, and an
expiration time 536. The control key KD1 528 is shared with the
local host(s) 220 that will be used in association with the first
application. The control key KD1 528 is used by the local host 220
and credential 216 to authenticate with one another. The control
schedule 532 is a logical combination of the credential's 216
access permissions by time as well as the credential's 216 access
permission by local host 220. The access decision application 416
uses the control schedule 532 to determine if access should be
granted or denied for the holder of the credential 216 with respect
to a particular reader/writer 212 or local host 220. The expiration
536 controls the useful life of the application data and is
generally only updated by the validation server 208. If the
expiration 536 has lapsed or expired then the control schedule 532
is rendered invalid until it is presented to a validation server
208 and the expiration 536 is updated again. The credential 216
will be incapable of making an access decision for any local host
in the first application if the expiration 536 for that application
has caused the control schedule 532 to be rendered invalid.
[0059] More than one set of application data may be stored in the
access decision application 416. A second set of application data
may include a control key KD2 540, a control schedule 544, and an
expiration 548. The second set of application data is substantially
unique to the second application and thus preferably runs the
second application independent of the first application. For
example, the lapse of the first expiration 536 does not necessarily
mean that the second expiration 548 has lapsed.
[0060] Although two application data blocks are depicted in FIG. 5,
one skilled in the art will appreciate that a lesser or greater
number of application data blocks may reside on the credential 216.
In one embodiment, there may be a different application data block
for each local host 220 in the secure access system 200.
[0061] In addition to application data, the access decision
application 416 may also store access history in a log file 552.
The log file 552 contains data related to access decisions made by
the credential 216. Both access granted decisions and access denial
decisions along with the corresponding time of decision and
reader/writer 212 or local host 220 are stored in the log file 552.
The log file 552 can be accessed to determine the whereabouts and
actions of the holder of the credential 216.
[0062] A timestamp 556 may also be stored as a part of the access
decision application 416. The timestamp 556 represents the most
recent time that the credential 216 was accessed by a reader/writer
212 or local host 220. Comparison of the timestamp 556 and
expiration 536, 548 may determine whether a particular application
should be rendered invalid by deactivating the control schedule
532, 544.
[0063] The privilege server 204 generally stores data for managing
the privileges of the population of credentials 216. The type of
data available to the privilege server 204 for each credential 216
in the population of credentials 216 may include a privilege key Kp
572, an application key Ka 576, a credential ID list with access
permissions data 580, and the current time 584. The data for all
credentials 216 may be stored in a separate database that can be
accessed by the privilege server 204. The privilege server 204
identifies a particular credential 216 and pulls relevant data for
that credential 216 into the fields described above using the
privilege key Kp 572. The privilege server 204 employs the
application key Ka 576 to authenticate with the credential 216.
Once the privilege server 204 is authenticated using the
application key Ka 576, the privilege server 204 can modify the
access decision application 416 and any application data associated
therewith.
[0064] The use of the keys Kp 572 and Ka 576 may involve the
transmission of an encrypted random or pseudorandom message. The
privilege server 204 typically has a random number generator and in
the event that the credential 216 does not have a random number
generator, the privilege server 204 can provide the random message
for the credential 216 to use in authentication.
[0065] As noted above, once the privilege server 204 has identified
the credential 216 and has pulled the relevant access permissions
data 580, the privilege server 204 can write or modify the access
decision application 416 along with the current time 584. The
current time 584 may be stored by the credential 216 as the
timestamp 556.
[0066] The validation server 208 generally stores data for managing
the expiration of application data on credentials 216. The type of
data available to the validation server 208 for each credential 216
in the population of credentials 216 may include an application key
Ka 560, a credential status 564, and the current time 568. The
validation server 208 employs the credential status 564 data to
determine if the credential's 216 expirations 536, 548 should be
updated or removed. The current time from the validation server 208
may also be written to the timestamp 556 data field in the access
decision application 416.
[0067] Each local host 220a-N may store unique data to the host or
the application employed by the host in their respective memories
316a-N. The type of data stored in a local host 220 may include a
local host ID 586, a control key KD1 590, and the current time 594.
The control key KD1 590 is used to authenticate with a credential
216 and more specifically to authenticate with a particular set of
application data stored in the application decision application
416. Once authenticated, the local host ID 586 and current time 594
are provided to the credential 216 such that an access decision can
be made by the credential 216.
[0068] Referring now to FIG. 6, a method of initializing a
credential 216 will be described in accordance with at least some
embodiments of the present invention. Initially, the method begins
with the privilege server 204 authenticating with the credential
216 (step 604). The privilege server 204 uses its privilege key Kp
572 and the credential 216 uses its privilege key Kp 508 to
authenticate with one another. As noted above, the authentication
step may involve the transmission of an encrypted random message
between the credential 216 and privilege server 204.
[0069] Once the privilege server 204 and credential 216 are
properly authenticated, the privilege server 204 acquires the
credential ID 504 from the credential 216 (step 608). The privilege
server 204 references a credential database with the credential ID
504 to eventually pull the access permissions for the particular
credential 216 (or holder of the credential 216) presented to the
privilege server 204. The privilege server 204 then creates the
access decision application 416 (step 612). The access decision
application 416 includes at least one set of application data. More
sets of application data may be included in the access decision
application 416 if more than one application is to be run by the
same credential 216.
[0070] After the access decision application 416 has been created,
the privilege server 204 assigns a unique user ID 524 to the
application (step 616). Other devices in the network 200 will
ultimately use the unique user ID 524 to determine if the
application 416 is still valid. The privilege server 204 then
retrieves the associated user access permissions data 580 from the
network using the credential ID 504 (step 620). The user access
permissions data 580 define what reader/writers 212 or local hosts
220 the user is allowed to access and the times the user is allowed
to access them. This user access permissions data 580 along with
the user ID 524 is written to the credential 216 as a part of the
access decision application 416 (step 624).
[0071] Upon writing the application to the card, or soon
thereafter, the privilege server 204 also writes expirations 536,
548 for each set of application data included in the access
decision application (step 628). The expirations 536, 548 can be a
timing based instruction to either delete a particular set of
application data or render the corresponding control schedule 532
invalid and thus unusable. After a set of application data has
expired, the credential 216 will need to be presented to a
reader/writer 212 such that either a privilege server 204 or
validation server 208 can update the expirations 536, 548.
Alternatively, the expirations 536, 548 may be valid and can remain
unchanged. It should be noted that separate access decision
applications for separate application data may be sequentially or
simultaneously created.
[0072] Referring now to FIG. 7, a method of refreshing an access
decision application 416 will be described in accordance with at
least some embodiments of the present invention. Initially, a
credential 216 is presented to the validation server 208 (step
704). The presentation of the credential 216 to the validation
server 208 may be through a communication conduit provided by a
reader/writer 212. Upon presentation of the credential 216 to the
validation server 208, authentication between the credential 216
and the validation server 208 occurs (step 708). The credential 216
uses application key Ka 520 to authenticate with the validation
server 208 and the validation server 208 uses application key Ka
560 to authenticate with the credential 216. The application keys
Ka 520, 560 are shared symmetric keys unique to the access decision
application 416. The authentication step helps ensure that both
devices know they are communicating with a valid device.
[0073] After mutual authentication, the validation server 208
acquires the user ID 524 from the credential 216 (step 712). Using
the user ID 524, the validation server 208 acquires the application
data for the presented credential 216 or holder of the credential
216 (step 716). The application data for the presented credential
216 can be obtained from periodic updates of the user's application
data from the privilege server 204 or by accessing the privilege
server 204 in real-time. The validation server 208 then analyzes
the application data for the presented credential 216 to determine
if the access permissions for that credential 216 are still valid
(step 720). In the event that the access permissions are no longer
valid, then the validation server 208 invalidates the control
schedule(s) 532, 544 that were identified as inactive (step 724).
Access permissions may become invalid for a number of reasons. For
example, the holder of the credential 216 may have been terminated
or had his/her permissions changed and therefore the application
data stored on the credential 216 is out no longer valid.
Alternatively, the access permissions may require updating and the
application data has not been updated within the predetermined
time.
[0074] The control schedule 532, 544 can be invalidated by
executing the expiration function 536, 548 corresponding to the
inactive control schedule 532, 544. Alternatively, access to the
control schedule 532, 544 can be restricted thus inhibiting the
credential 216 from making an access decision. In one embodiment, a
control schedule 532, 544 is marked invalid by setting the
timestamp to all zeros. In another embodiment control schedules
532, 544 are marked invalid by setting the expiration to a time in
the past or to a different prescribed invalid code.
[0075] In the event that the access permissions are still valid,
the method continues and the validation server 208 updates the
schedule expiration 536, 548 if appropriate or necessary (step
728). The expiration 536, 548 may be updated both in the network as
well as the credential 216. The reader/writer 212 may be used to
write the updated expiration 536, 548 to the credential 216.
Updating the expiration 536, 548 may include adding additional time
to the expiration counter or changing the expiration date.
[0076] Once the expiration 536, 548 has been updated, the
validation server 208 sends an approval signal back to the
reader/writer 212 (step 732). The reader/writer 212 may then grant
the holder of the credential 216 access to the asset protected by
the reader/writer 212. Alternatively, a light or similar type of
indicator may be activated showing the credential 216 holder that
the expiration 536, 548 has been successfully updated.
[0077] With reference now to FIG. 8, a method of operating a local
host 220 will be described in accordance with at least some
embodiments of the present invention. Initially, when a credential
216 is presented to a local host 220, the local host 220 transmits
its local host ID 586 to the credential 216 (step 804). The local
host ID 586 uniquely identifies the local host 220 or the
application employed by the local host 220 to the credential 216.
Upon receipt of the local host ID 586, the credential 216 locates
the local host ID 586 in its application data 416 (step 808). More
specifically, the credential 216 identifies that the local host ID
586 is being used in connection with the access decision
application 416 and the control schedules 532, 544 of each set of
application data is searched for a matching local host ID 586. When
the local host ID 586 is found, the control key KD 528, 540 is
pulled from the corresponding set of application data. The chosen
control key KD 528, 540 is used by the credential 216 to
authenticate with the local host 220 (step 812).
[0078] After the credential 216 and local host 220 have mutually
authenticated with one another, the local host 220 reads the
timestamp data 556 from the credential 216 (step 816). The local
host 220 uses the timestamp 556 to determine if its own current
time 594 is way off from the actual time (assuming the timestamp
556 accurately reflects actual time). The local host 220 can use
the timestamp 556 to perform an option step where the local host
220 checks to see if the timestamp 556 is greater than the current
time 594 (step 820). The optional step 820 is provided as a check
to ensure that the local host 220 clock is not running too slow. In
the event that the timestamp 556 is greater than the current time
594, then the local host 220 updates its current time 594. The
assumption behind the local host 220 updating its time to match the
time from the timestamp 556 is because the credential 216 is able
to communicate with networked devices such as a reader/writer 212
that receive their current time from a live and presumably more
accurate source such as the Internet. Therefore, the credential 216
timestamp 556 can be updated whenever it is presented to a
networked device.
[0079] Once the current time 594 is updated or determined to be
accurate, the local host 220 transmits the current time 594 to the
credential 216 (step 828). The credential 216 then uses the access
decision application 416 to compare the received current time
against the control schedule 532, 544 for the appropriate
application (step 832). After running the access decision
application 416 the credential 216 determines whether it is allowed
to access the asset protected by the local host 220. In other
words, the access decision application 416 determines whether the
current time 594 is within the control schedule 532, 544 for the
asset associated with the local host (step 836). In other words,
the access decision application 416 may determine if access is
granted to the local host 220 as well as specify that access is
currently allowed for the local host 220 to which the credential
216 is presented. If the current time is not within the control
schedule 532, 544 (i.e., the credential 216 is not allowed access
to the asset), then no action is performed or the credential 216
sends a denied access message to the local host 220 (step 840). On
the other hand, if the credential 216 determines that it should be
allowed access to the asset based on the analysis of the control
schedule 532, 544, then the credential 216 sends an access granted
message to the local host 220 (step 844). Upon receipt of the
access granted message, the local host 220 activates an access
control device 312 permitting the holder of the credential 216 to
access the asset (step 848). The activation of the access control
device 312 may include unlocking a lock, releasing a latch, or
permitting access to a financial or electronic file.
[0080] FIG. 9 depicts a communications diagram between a credential
216 and a local host 220 in accordance with at least some
embodiments of the present invention. Initially, the credential 216
and local host 220 mutually authenticate with one another (step
904). After mutual authentication has occurred, the local host 220
encrypts a number of different pieces of data together into a
message (step 908). The encrypted data may include a random number
(Rand), the local host ID 586 (LockID), and current time
information. After the message and its contents are properly
encrypted, the local host 220 transmits the encrypted message (step
912).
[0081] In step 916, the encrypted message is received by the
credential 216. After the credential 216 receives the encrypted
message it passes the message to the controller 408 where the
message is decrypted (step 920). Any known type of
encryption/decryption scheme, whether symmetric or asymmetric, may
be employed to protect the message during transmission.
[0082] After the message has been decrypted, the controller 408
runs the appropriate access decision application 416 (step 924), as
the memory may contain multiple access decision applications. Part
of running the access decision application 416 generally includes
making an access decision and generating a message consistent with
the decision (step 928). For example, if an access granted decision
is made by the credential 216, then a grant access message is
generated. Alternatively, if an access denied decision is made by
the credential 216, then a deny access message is generated. The
controller 408 then encrypts the contents of the message according
to either the same encryption protocol that was employed by the
local host 220 or a different encryption protocol (step 932).
Thereafter, the controller 408 sends the encrypted message to the
communication interface 404 for transmission (step 936).
[0083] The message transmitted by the credential 216 is
subsequently received by the local host 220 (step 940). After the
message is received, the controller 308 decrypts the message (step
944). Thereafter, the contents of the decrypted message are stored
in memory 216 of the local host 220 (step 948). Of course, the
contents of the message may have also been stored in the log file
552 of the credential 216 prior to transmission of the message.
[0084] The local host 220 then sends a control signal to the access
control device 312 causing the access control device 312 to act in
accordance with the access decision made by the credential 216
(step 952). In other words, if the credential 216 decided that
access should be granted, then the access control device 312 is
manipulated such that access to the asset protected by the local
host 220 can be obtained. However, if the credential 216 decided
that access should be denied, then the access control device 312 is
manipulated or left alone such that access to the asset is
denied.
[0085] In accordance with other embodiments of the present
invention, the credential 216 may have access to a positioning
satellite signal. In such an embodiment, the credential 216 can
infer what local host 220 it is talking to based on its known
position. This eliminates the requirement of the local host 220
providing a local host ID to the credential 216. The satellite may
also provide the current time to the credential 216 such that the
credential 216 could make an access decision without receiving any
information from the local host 220. Mutual authentication and an
access decision message transmission from the credential 216 to the
local host 220 would be the only communications required between
the credential 216 and the local host 220.
[0086] In other alternative embodiments, the application data is
protected with a public-key cryptography using an asymmetric key Ka
unique to a particular application. The key Ka would be shared with
the privilege server 204. Alternatively, the key is a symmetric key
diversified from a master key. In such a scheme, the privilege
server 204 knows public information such as a User ID 524. The
secret diversified key is derived from the public information using
a hash or encryption algorithm with a secret master key known only
to the privilege server 204. The diversified key is pre-calculated
and stored on the credential 216 and calculated by the privilege
server 204 during authentication.
[0087] In one embodiment, the authentication is performed on a
static or rolling message exchanged between the credential 216 and
the reader/writer 212 or local host 220. In another embodiment, the
reader/writer 212 or local host 220 could have a random number
generator that would be used to create a random message to use in
the authentication.
[0088] In another embodiment, the user ID 524 assigned for a
particular application is replaced with the credential ID 504,
which could be read and cross-referenced with the user information
for the purpose of assigning privileges.
[0089] In another embodiment, the reader/writer 212 or local host
220 could also be equipped with a secondary authentication device
that requires a personal identification number (PIN). Either the
credential 216 would read the PIN and compare it with a stored
value as part of the access decision or the credential would
transmit its stored value to the reader so that the reader could
compare PIN values as part of the access decision.
[0090] In still another embodiment, biometric identification
information can be stored on the credential and compared to a live
scan biometric identification obtained either by the credential or
transmitted from an external scanner. The credential 216 performs a
match between the stored and live scan biometric data and uses the
positive or negative comparison as part of the access decision.
Alternatively, authentication is performed using a session key
transported to the local host 220 by the credential 216 using a
Kerberos scheme.
[0091] In accordance with one embodiment of the present invention,
the control schedule 532 uses an area control scheme requiring the
credential 216 to track its recent usage history. In an area
control scheme a pair of area numbers is associated with the local
host 220. For example, each local host 220 is a portal permitting
egress from one area, and ingress to another area. This area
control information is written to the credential 216 by the
validation server 208 and may be in the form of last area entered
and/or a timestamp from the access granting event to the last area
entered.
[0092] In yet another embodiment where the local host 220 does not
have access to a clock, the application data may contain a counter
that permits a specified number of accesses with a given local host
ID 586. The number is counted down each time that access is given
for local host ID 586 and the permission is denied after the
counter reaches a lower limit, such as zero. Alternatively, the
credential 216 may be set to expire by means of a decay constant.
The decay constant could be electric charge leaving a capacitor or
battery, magnetic field, or other means that can be detected and
reset.
[0093] In still another embodiment, the application data is stored
on the credential 216 in a structured order, for example a door
list in column 1, a two-man-rule name list in column 2, and other
information in column 3 and so on. Then a filter that is coded to
read data from a given column/row on the credential 216 may be
stored on the local host 220. This template contains no other
information other than which row and column to read from a
credential 216. This template can be stored on the local host 220
memory 316. In use for decision-on-card, the template will be read
by the credential 216 and the identified information will be used
in making the access decision.
[0094] As can be appreciated by one skilled in the art, additional
applications may be employed using a credential 216 that is capable
of making its own access decisions. In one embodiment, the
credential 216 may be used for loyalty programs that, for example,
offer a free or discounted product or service after a prescribed
number of products or services have been purchased.
[0095] Two-Man-Rule on Reader
[0096] The two-man-rule controls access to sensitive areas where a
minimum of two people are required at all times. Most of the logic
is contained in the reader/writer 212 or local host 220. The access
control device 312 is normally locked and two valid credentials 216
are presented for entry. Either two readers can be used to ensure
near simultaneity or a single reader can be used to read two
credentials 216 in temporally close succession. The reader notes
that two valid credentials 216 have been read and then once the
access control device 312, such as a door, has been opened and
closed, a reader on the opposite side of the door must again read
the same two credentials 216 to ensure that both users entered.
Once two users are in the secure area, additional valid users are
allowed access. Exiting the secure area follows the same procedure
in reverse where the last two people must exit together or where no
single individual is permitted to remain in the searched area. Any
violation of the procedure will set off an alarm. Log files may be
kept on both the reader and the credentials 216. The information
stored on the credential 216 can include the identification of
other credentials 216 used to enter the room during the same time
period. This method requires that the reader has a way of detecting
that the door or similar access control device 312 has been closed
and locked.
[0097] Two-Man-Rule on Credential
[0098] An alternative approach is to put the two-man-rule on the
credential 216. In one embodiment, two valid credentials 216 are
presented to an outside reader. The credential 216 recognizes that
the reader uses two-man-rule and the reader has to cooperate with
the credentials 216 by providing information to the second
credential 216 that a valid first credential 216 has just been
read. The reader can be programmed to use the two-man-rule by
transmitting the timestamp of the most recently read valid
credential 216 and by having the ability to interpret two different
control commands from the credential 216. One possible control
command is that the credential 216 is valid but without the command
to unlock the door. This occurs when a credential 216 verifies that
it is valid, but that the timestamp received from the reader of the
most recent valid credential 216 is too old (for example more than
five seconds). The second control command, for example, is to
unlock the access control device 312. This occurs when the
credential 312 verifies that it is valid and that the timestamp
from the most recently read valid credential 312 is within the
allowed time period defined in the two-man-rule. An example
two-man-rule is shown as follows:
[0099] 1) The first valid credential 216 sends a message to the
reader that it is valid and the reader does not immediately unlock
the door but instead waits for a second valid credential 216.
[0100] 2) The second credential 216 receives information from the
reader a first credential 216 has just been validated.
[0101] 3) The second credential 216 has information that this door
uses two-man-rule and should, after receiving information about the
first valid credential 216, check its own validity with a positive
check resulting in the credential 216 sending a control command for
the access control device 312 to be unlocked or released.
[0102] Man-Trap
[0103] A man-trap provides security against piggybacking. The
configuration requires two doors on either side of a vestibule area
and each door having a reader on both the inside and outside of the
area. Both doors are normally locked and are generally unlocked in
a specified order. Normal operation requires that readers on both
doors are able to detect if either of the other doors are closed
and locked or open. In normal operation, a credential 216 is
presented to a first reader outside the enclosed area on or near
the first door. A valid credential 216 will unlock this first door
allowing the person to enter the vestibule. The first door closes
and locks before the second door can be unlocked. After the first
door is closed and locked the credential 216 can be presented to
the second door and, if valid, the second door will unlock.
[0104] Pseudo Man Trap
[0105] A pseudo-man-trap can be implemented on non-networked
readers. With non-networked readers, the second door is unaware of
whether or not the first door is closed and locked or is open;
therefore, it cannot be required to remain locked while the first
door is open or unlocked (this may be overcome by a local wired or
wireless network). Similar results can be obtained by using the
credential 216 to carry a message from the first door to the second
door regarding its lock-status. The operation of a pseudo-man-trap
is described as follows:
[0106] 1) The credential 216 is presented to the outside reader of
the first door and if valid the door is unlocked.
[0107] 2) After entering the enclosure and waiting for the door to
close and lock, the credential 216 is presented to the inside
reader of the first door. The card receives a secure message,
possibly using a key shared by the two doors, stating that the
first door is closed and locked.
[0108] 3) The credential 216 is presented to the second door and
both the credential 216 validation and the first-door-status are
checked. If both conditions are satisfied the second door is
unlocked.
[0109] The present invention, in various embodiments, includes
components, methods, processes, systems and/or apparatus
substantially as depicted and described herein, including various
embodiments, subcombinations, and subsets thereof. Those of skill
in the art will understand how to make and use the present
invention after understanding the present disclosure. The present
invention, in various embodiments, includes providing devices and
processes in the absence of items not depicted and/or described
herein or in various embodiments hereof, including in the absence
of such items as may have been used in previous devices or
processes, e.g., for improving performance, achieving ease and\or
reducing cost of implementation.
[0110] The foregoing discussion of the invention has been presented
for purposes of illustration and description. The foregoing is not
intended to limit the invention to the form or forms disclosed
herein. In the foregoing Detailed Description for example, various
features of the invention are grouped together in one or more
embodiments for the purpose of streamlining the disclosure. This
method of disclosure is not to be interpreted as reflecting an
intention that the claimed invention requires more features than
are expressly recited in each claim. Rather, as the following
claims reflect, inventive aspects lie in less than all features of
a single foregoing disclosed embodiment. Thus, the following claims
are hereby incorporated into this Detailed Description, with each
claim standing on its own as a separate preferred embodiment of the
invention.
[0111] Moreover though the description of the invention has
included description of one or more embodiments and certain
variations and modifications, other variations and modifications
are within the scope of the invention, e.g., as may be within the
skill and knowledge of those in the art, after understanding the
present disclosure. It is intended to obtain rights which include
alternative embodiments to the extent permitted, including
alternate, interchangeable and/or equivalent structures, functions,
ranges or steps to those claimed, whether or not such alternate,
interchangeable and/or equivalent structures, functions, ranges or
steps are disclosed herein, and without intending to publicly
dedicate any patentable subject matter.
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