U.S. patent application number 11/624079 was filed with the patent office on 2007-06-14 for method to protect software against unwanted use with a detection and coercion principle.
This patent application is currently assigned to SAS VALIDY. Invention is credited to Jean-Christophe Emanuel CUENOD, Gilles Jean SGRO.
Application Number | 20070136816 11/624079 |
Document ID | / |
Family ID | 26874812 |
Filed Date | 2007-06-14 |
United States Patent
Application |
20070136816 |
Kind Code |
A1 |
CUENOD; Jean-Christophe Emanuel ;
et al. |
June 14, 2007 |
METHOD TO PROTECT SOFTWARE AGAINST UNWANTED USE WITH A DETECTION
AND COERCION PRINCIPLE
Abstract
The invention concerns a process to protect a vulnerable
software working on a data processing system against its
unauthorized usage using a processing and memorizing unit. The
process comprises defining: 1) at least one software execution
characteristic, liable to be monitored at least in part in a
processing and memorizing unit 2) at least one criterion to abide
by for at least one software execution characteristic 3) detection
means to implement in a processing and memorizing unit and enabling
to detect that at least one software execution characteristic does
not abide by at least one associated criterion 4) coercion means to
implement in a processing and memorizing unit and enabling to
inform the data processing system and/or modify the execution of a
software when at least one criterion is not abided by.
Inventors: |
CUENOD; Jean-Christophe
Emanuel; (Montesson, FR) ; SGRO; Gilles Jean;
(Bourg De Peage, FR) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
SAS VALIDY
ZI, 5 RUE JEAN CARCOT
ROMANS SUR ISERE
FR
26100
|
Family ID: |
26874812 |
Appl. No.: |
11/624079 |
Filed: |
January 17, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10178918 |
Jun 25, 2002 |
7174466 |
|
|
11624079 |
Jan 17, 2007 |
|
|
|
60308834 |
Aug 1, 2001 |
|
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|
Current U.S.
Class: |
726/26 |
Current CPC
Class: |
G06F 21/123
20130101 |
Class at
Publication: |
726/026 |
International
Class: |
H04N 7/16 20060101
H04N007/16 |
Claims
1. A process to protect, using at least one blank unit (60)
including at least memorization means (15) and processing means
(16), a vulnerable software (2v) against its unauthorized usage,
said vulnerable software (2v) being produced from a source (2vs)
and working on a data processing system (3), said protection
process comprising: during a protection phase (P): defining: at
least one software execution characteristic, liable to be monitored
at least in part in a unit (6), at least one criterion to abide by
for at least one software execution characteristic, detection means
(17) to implement in a unit (6) and enabling to detect that at
least one software execution characteristic does not abide by at
least one associated criterion, and coercion means (18) to
implement in a unit (6) and enabling to inform the data processing
system (3) and/or modify the execution of a software when at least
one criterion is not abided by, constructing exploitation means
enabling to transform the blank unit (60) into a unit (6) able to
implement the detection means (17) and the coercion means (18),
creating a protected software (2p): by choosing at least one
software execution characteristic to monitor, among the software
execution characteristics liable to be monitored, by choosing at
least one criterion to abide by for at least one chosen software
execution characteristic, by choosing, at least one algorithmic
processing which, during the execution of the vulnerable software
(2v), uses at least one operand and enables to obtain at least one
result, and for which at least one chosen software execution
characteristic, is to be monitored, by choosing at least one
portion of the source of the vulnerable software (2vs) containing,
at least one chosen algorithmic processing, by producing the source
of the protected software (2ps) from the source of the vulnerable
software (2vs), by modifying at least one chosen portion of the
source of the vulnerable software (2vs) to obtain at least one
modified portion of the source of the protected software (2ps),
this modification being such that: during the execution of the
protected software (2p) a first execution part (2pes) is executed
in the data processing system (3) and a second execution part
(2peu) is executed in a unit (6), obtained from the blank unit (60)
after upload of information, the second execution part (2peu)
executes at least the functionality of at least one chosen
algorithmic processing, and during the execution of the protected
software (2p), at least one chosen execution characteristic is
monitored by means of the second execution part (2peu) and the fact
that a criterion is not abided by leads to a modification of the
execution of the protected software (2p), and by producing: a first
object part (2pos) of the protected software (2p), from the source
of the protected software (2ps), said first object part (2pos)
being such that during the execution of the protected software
(2p), appears a first execution part (2pes) which is executed in
the data processing system (3) and whose at least a portion takes
into account that at least one chosen software execution
characteristic is monitored, and a second object part (2pou) of the
protected software (2p), containing the exploitation means
implementing the detection means (17) and the coercion means (18),
said second object part (2pou) being such that, after upload to the
blank unit (60) and during the execution of the protected software
(2p), appears the second execution part (2peu) by means of which at
least one chosen software execution characteristic is monitored and
by means of which the fact that a criterion is not abided by leads
to a modification of the execution of the protected software (2p),
and uploading the second object part (2pou) to the blank unit (60),
with the intention of obtaining the unit (6), and during a usage
phase (U) during which the protected software (2p) is executed: in
the presence of the unit (6): and as long as all the criteria
corresponding to all the monitored execution characteristics of all
the modified portions of the protected software (2p) are abided by,
enabling said portions of the protected software (2p) to work
nominally and consequently enabling the protected software (2p) to
work nominally, and if at least one of the criteria corresponding
to a monitored execution characteristic of a portion of the
protected software (2p) is not abided by, informing the data
processing system (3) of it and/or modifying the functioning of the
portion of the protected software (2p), so that the functioning of
the protected software (2p) is modified, and in the absence of the
unit (6), in spite of the request by a portion of the first
execution part (2pes) to trigger the execution in the unit (6), of
the functionality of a chosen algorithmic processing, in not being
able to fulfill said request correctly, so that at least said
portion is not executed correctly and that, consequently, the
protected software (2p) is not completely functional, wherein
during the protection phase (P): defining: as software execution
characteristic liable to be monitored, a profile of software usage,
and as criterion to abide by, at least one feature of software
execution, and modifying the protected software (2p): by choosing
as software execution characteristic to monitor at least one
profile of software usage, by choosing at least one feature of
execution by which at least one chosen profile of usage must abide,
and by modifying at least one chosen portion of the source of the
protected software (2ps), this modification being such that, during
the execution of the protected software (2p), the second execution
part (2peu) abides by all the chosen features of execution, and
during the usage phase (U) in the presence of the unit (6), and in
the case where it is detected that at least one feature of
execution is not abided by, informing the data processing system
(3) of it and/or modifying the functioning of the portion of the
protected software (2p), so that the functioning of the protected
software (2p) is modified, wherein during the protection phase (P):
defining: an instructions set whose instructions are liable to be
executed in the unit (6), a set of instructions commands for said
instructions set, said instructions commands being liable to be
executed in the data processing system (3) and to trigger in the
unit (6) the execution of the instructions, as profile of usage,
the chaining of the instructions, as feature of execution, an
expected chaining for the execution of the instructions, as
detection means (17), means enabling to detect that the chaining of
the instructions does not correspond to the expected one, and as
coercion means (18), means enabling to inform the data processing
system (3) and/or to modify the functioning of the portion of
protected software (2p) when the chaining of the instructions does
not correspond to the expected one, constructing the exploitation
means also enabling the unit (6) to execute the instructions of the
instructions set, the execution of said instructions being
triggered by the execution in the data processing system (3), of
the instructions commands, and modifying the protected software
(2p): by modifying at least one chosen portion of the source of the
protected software (2ps), this modification being such that: at
least one chosen algorithmic processing is split so that during the
execution of the protected software (2p), said algorithmic
processing is executed by means of the second execution part
(2peu), using instructions, for at least one chosen algorithmic
processing, instructions commands are integrated to the source of
the protected software (2ps), so that during the execution of the
protected software (2p), each instruction command is executed by
the first execution part (2pes) and triggers in the unit (6), the
execution by means of the second execution part (2peu), of an
instruction, a sequence of the instructions commands is chosen
among the set of sequences allowing the execution of the protected
software (2p), and the chaining by which must abide at least some
of the instructions during their execution in the unit (6) is
specified, and during the usage phase (U), in the presence of the
unit (6), in the case where it is detected that the chaining of the
instructions executed in the unit (6) does not correspond to the
expected one, informing the data processing system (3) of it and/or
modifying the functioning of the portion of the protected software
(2p), so that the functioning of the protected software (2p) is
modified, wherein during the protection phase (P): defining: as
instructions set, an instructions set whose at least some
instructions work with registers and use at least one operand with
the intention of returning a result, for at least some of the
instructions working with registers: a part (PF) defining the
functionality of the instruction, and a part defining the expected
chaining for the execution of the instructions and including bits
fields corresponding to: an identification field of the instruction
(CII), and for each operand of the instruction: a flag field
(CD.sub.k), and an expected identification field (CIP.sub.k) of the
operand, for each register belonging to the exploitation means and
used by the instructions set, a generated identification field
(CIG.sub.v) in which is automatically memorized the identification
of the last instruction which has returned its result in said
register, as detection means (17), means enabling, during the
execution of an instruction, for each operand, when the flag field
(CD.sub.k) imposes it, to check the equality of the generated
identification field (CIG.sub.v) corresponding to the register used
by said operand, and the expected identification field (CIP.sub.k)
of the origin of said operand, and as coercion means (18), means
enabling to modify the result of the instructions, if at least one
of the checked equalities is false, and wherein for each said
operand, said flag field (CD.sub.k) abd saud expected
identification field (CIP.sub.k) are merged into a tag field and at
least one value of each said tag field is used to indicate that
equality with said generated identification field (CIG.sub.v) shall
not be checked.
2. A method to protect software comprising: storing a first portion
of the software on a first unit, wherein the first unit comprises a
memory and a processor; storing a second portion of the software on
a second unit, wherein the second unit comprises a secure processor
and a secure memory, wherein the second portion of the software is
secret, and wherein the first and second portions of the software
form a single executable program; and executing the program,
wherein operations performed during the execution comprise: the
first portion provides input to the second portion, the second
portion provides a result to the first portion wherein the second
unit comprises a detection module that detects a software execution
characteristic of said operations performed during the execution
that does not abide to an associated criterion, and wherein, when
the detection module detects the none abiding software execution
characteristic, a coercion module of the second unit informs the
first unit of the none abiding software execution characteristic
and modifies the executed program.
3. The method according to claim 2, wherein the modification of the
executed program comprises stopping the execution of the
program.
4. The method according to claim 2, wherein the second unit is a
chip medium configured to attach and detach to the first unit.
5. The method according to claim 2, wherein the processor of the
second unit is a coprocessor of the processor of the first
unit.
6. The method according to claim 2, wherein the second unit is a
token.
7. The method according to claim 2, wherein, when the detection
module of the second unit detects that the result obtained by the
second portion does not abide to the associated criterion, the
coercion module of the second unit modifies the executed program to
stop the execution of the program.
8. A method to protect a vulnerable software working on a data
processing system against its unauthorized usage using a unit
comprising a processor and a memory and is configured to attach and
detach to the processing system, the method comprising: defining a
software execution characteristic liable to be monitored at least
in part in the unit; defining a criterion to abide by for said
software execution characteristic; detecting, in the unit, that the
defined software execution characteristic does not abide by the
defined associated criterion; and informing the data processing
system by the unit when the defined associated criterion is not
abided.
9. The method according to claim 8, further comprising modifying
the execution of a software when the defined associated criterion
is not abided by.
Description
BACKGROUND OF THE INVENTION
[0001] This invention concerns the technical domain of data
processing systems in the general sense, and is more precisely
aimed at the means of protecting software running on said data
processing systems against unauthorized usage.
[0002] The subject of the invention aims in particular at the means
of protecting software against unauthorized usage, using a
processing and memorizing unit, such a unit being commonly
materialized by a chip card or a material key on USB port.
[0003] In the technical domain above, the main problem concerns the
unauthorized usage of software by users who have not paid the
license rights. This illicit use of software causes an obvious loss
for software editors, software distributors and/or any person
integrating such software in products. To avoid such illicit
copies, various solutions, in the state of technology, have been
proposed to protect software.
[0004] Thus, a protection solution is known, which makes use of a
hardware protection system, such as a physical component named
protection key or "dongle". Such a protection key should guarantee
that the software executes only in presence of the key. Yet, it
must be acknowledged that this solution is ineffective because it
presents the inconvenience of being easy to bypass. An
ill-intentioned person or a hacker can, with the aid of specialized
tools such as disassemblers, delete the control instructions of the
protection key. It becomes then possible to make illicit copies
corresponding to modified versions of the software able to run
without the protection. Moreover, this solution cannot be
generalized to all software, inasmuch as it is difficult to connect
more than two protection keys to the same system.
BRIEF SUMMARY OF THE INVENTION
[0005] The subject of the invention aims precisely at finding a
solution to the aforementioned problems by proposing a process to
protect a software against unauthorized usage, using an ad hoc
processing and memorizing unit, inasmuch as the presence of such a
unit is necessary for the software to be completely functional.
[0006] So as to reach such a goal, the subject of the invention
concerns a process to protect, using at least one blank unit
including at least processing means and memorization means, a
vulnerable software against its unauthorized usage, said vulnerable
software being produced from a source and working on a data
processing system. The process according to the invention
comprises: [0007] during a protection phase: [0008] defining:
[0009] at least one software execution characteristic, liable to be
monitored at least in part in a unit, [0010] at least one criterion
to abide by for at least one software execution characteristic,
[0011] detection means to implement in a unit and enabling to
detect that at least one software execution characteristic does not
abide by at least one associated criterion, [0012] and coercion
means to implement in a unit and enabling to inform the data
processing system and/or modify the execution of a software when at
least one criterion is not abided by, [0013] constructing
exploitation means enabling to transform the blank unit into a unit
able to implement the detection means and the coercion means,
[0014] creating a protected software: [0015] by choosing at least
one software execution characteristic to monitor, among the
software execution characteristics liable to be monitored, [0016]
by choosing at least one criterion to abide by for at least one
chosen software execution characteristic, [0017] by choosing, at
least one algorithmic processing which, during the execution of the
vulnerable software, uses at least one operand and enables to
obtain at least one result, and for which at least one chosen
software execution characteristic, is to be monitored, [0018] by
choosing at least one portion of the source of the vulnerable
software containing, at least one chosen algorithmic processing,
[0019] by producing the source of the protected software from the
source of the vulnerable software, by modifying at least one chosen
portion of the source of the vulnerable software to obtain at least
one modified portion of the source of the protected software, this
modification being such that: [0020] during the execution of the
protected software a first execution part is executed in the data
processing system and a second execution part is executed in a
unit, obtained from the blank unit after upload of information,
[0021] the second execution part executes at least the
functionality of at least one chosen algorithmic processing, [0022]
and during the execution of the protected software, at least one
chosen execution characteristic is monitored by means of the second
execution part and the fact that a criterion is not abided by leads
to a modification of the execution of the protected software,
[0023] and by producing: [0024] a first object part of the
protected software, from the source of the protected software, said
first object part being such that during the execution of the
protected software, appears a first execution part which is
executed in the data processing system and whose at least a portion
takes into account that at least one chosen software execution
characteristic is monitored, [0025] and a second object part of the
protected software, containing the exploitation means implementing
the detection means and the coercion means, said second object part
being such that, after upload to the blank unit and during the
execution of the protected software, appears the second execution
part by means of which at least one chosen software execution
characteristic is monitored and by means of which the fact that a
criterion is not abided by leads to a modification of the execution
of the protected software, [0026] and uploading the second object
part to the blank unit, with the intention of obtaining the unit,
[0027] and during a usage phase during which the protected software
is executed: [0028] in the presence of the unit: [0029] and as long
as all the criteria corresponding to all the monitored execution
characteristics of all the modified portions of the protected
software are abided by, enabling said portions of the protected
software to work nominally and consequently enabling the protected
software to work nominally, [0030] and if at least one of the
criteria corresponding to a monitored execution characteristic of a
portion of the protected software is not abided by, informing the
data processing system of it and/or modifying the functioning of
the portion of the protected software, so that the functioning of
the protected software is modified, [0031] and in the absence of
the unit, in spite of the request by a portion of the first
execution part to trigger the execution in the unit, of the
functionality of a chosen algorithmic processing, in not being able
to fulfill said request correctly, so that at least said portion is
not executed correctly and that consequently, the protected
software is not completely functional.
[0032] According to a variant embodiment, the process according to
the invention comprises: [0033] during the protection phase: [0034]
defining: [0035] as software execution characteristic liable to be
monitored, a variable of measurement of the usage of a
functionality of a software, [0036] as criterion to abide by, at
least one threshold associated to each variable of measurement,
[0037] and actualization means enabling to update at least one
variable of measurement, [0038] constructing the exploitation means
enabling the unit to also implement the actualization means, [0039]
and modifying the protected software: [0040] by choosing as
software execution characteristic to monitor, at least one variable
of measurement of the usage of at least one functionality of a
software, [0041] by choosing: [0042] at least one functionality of
the protected software whose usage is liable to be monitored using
a variable of measurement, [0043] at least one variable of
measurement used to quantify the usage of said functionality,
[0044] at least one threshold associated to a chosen variable of
measurement corresponding to a limit of usage of said
functionality, [0045] and at least one method of update of a chosen
variable of measurement depending on the usage of said
functionality, [0046] and by modifying at least one chosen portion
of the source of the protected software, this modification being
such that, during the execution of the protected software, the
variable of measurement is actualized by means of the second
execution part depending on the usage of said functionality, and at
least one threshold crossing is taken into account, [0047] and
during the usage phase, in the presence of the unit, and in the
case where at least one threshold crossing corresponding to at
least one limit of usage is detected, informing the data processing
system of it and/or modifying the functioning of the portion of the
protected software, so that the functioning of the protected
software is modified.
[0048] According to a variant embodiment, the process according to
the invention comprises: [0049] during the protection phase: [0050]
a defining: [0051] for at least one variable of measurement,
several associated thresholds, [0052] and different coercion means
corresponding to each of said thresholds, [0053] and modifying the
protected software: [0054] by choosing in the source of the
protected software, at least one chosen variable of measurement to
which must be associated several thresholds corresponding to
different limits of usage of the functionality, [0055] by choosing
at least two thresholds associated to the chosen variable of
measurement, [0056] and by modifying at least one chosen portion of
the source of the protected software, this modification being such
that, during the execution of the protected software, the crossings
of the various thresholds are taken into account differently, by
means of the second execution part, [0057] and during the usage
phase: [0058] in the presence of the unit: [0059] in the case where
the crossing of a first threshold is detected, enjoining the
protected software not to use the corresponding functionality
anymore, [0060] and in the case where the crossing of a second
threshold is detected, making ineffective the corresponding
functionality and/or at least one portion of the protected
software.
[0061] According to a variant embodiment, the process according to
the invention comprises: [0062] during the protection phase: [0063]
defining refilling means enabling to credit at least one software
functionality monitored by a variable of measurement with at least
one additional usage, [0064] constructing the exploitation means
also allowing the unit to implement the refilling means, [0065] and
modifying the protected software: [0066] by choosing in the source
of the protected software, at least one chosen variable of
measurement enabling to limit the usage of a functionality and
which must be able to be credited with at least one additional
usage, [0067] and by modifying at least one chosen portion, this
modification being such that during a phase called of refilling, at
least one additional usage of at least one functionality
corresponding to a chosen variable of measurement can be credited,
[0068] and during the phase of refilling: [0069] reactualizing at
least one chosen variable of measurement and/or at least one
associated threshold, so as to allow at least one additional usage
of the functionality.
[0070] According to a variant embodiment, the process according to
the invention comprises: [0071] during the protection phase: [0072]
defining: [0073] as software execution characteristic liable to be
monitored, a profile of software usage, [0074] and as criterion to
abide by, at least one feature of software execution, [0075] and
modifying the protected software: [0076] by choosing as software
execution characteristic to monitor at least one profile of
software usage, [0077] by choosing at least one feature of
execution by which at least one chosen profile of usage must abide,
[0078] and by modifying at least one chosen portion of the source
of the protected software, this modification being such that,
during the execution of the protected software, the second
execution part abides by all the chosen features of execution,
[0079] and during the usage phase in the presence of the unit, and
in the case where it is detected that at least one feature of
execution is not abided by, informing the data processing system of
it and/or modifying the functioning of the portion of the protected
software, so that the functioning of the protected software is
modified.
[0080] According to a variant embodiment, the process according to
the invention comprises: [0081] during the protection phase: [0082]
defining: [0083] an instructions set whose instructions are liable
to be executed in the unit, [0084] a set of instructions commands
for said instructions set, said instructions commands being liable
to be executed in the data processing system and to trigger in the
unit the execution of the instructions, [0085] as profile of usage,
the chaining of the instructions, [0086] as feature of execution,
an expected chaining for the execution of the instructions, [0087]
as detection means, means enabling to detect that the chaining of
the instructions does not correspond to the expected one, [0088]
and as coercion means, means enabling to inform the data processing
system and/or to modify the functioning of the portion of protected
software when the chaining of the instructions does not correspond
to the expected one, [0089] constructing the exploitation means
also enabling the unit to execute the instructions of the
instructions set, the execution of said instructions being
triggered by the execution in the data processing system, of the
instructions commands, [0090] and modifying the protected software:
[0091] by modifying at least one chosen portion of the source of
the protected software, this modification being such that: [0092]
at least one chosen algorithmic processing is split so that during
the execution of the protected software, said algorithmic
processing is executed by means of the second execution part, using
instructions, [0093] for at least one chosen algorithmic
processing, instructions commands are integrated to the source of
the protected software, so that during the execution of the
protected software, each instruction command is executed by the
first execution part and triggers in the unit, the execution by
means of the second execution part, of an instruction, [0094] a
sequence of the instructions commands is chosen among the set of
sequences allowing the execution of the protected software, [0095]
and the chaining by which must abide at least some of the
instructions during their execution in the unit is specified,
[0096] and during the usage phase, in the presence of the unit, in
the case where it is detected that the chaining of the instructions
executed in the unit does not correspond to the expected one,
informing the data processing system of it and/or modifying the
functioning of the portion of the protected software, so that the
functioning of the protected software is modified.
[0097] According to a variant embodiment, the process according to
the invention comprises: [0098] during the protection phase: [0099]
defining: [0100] as instructions set, an instructions set whose at
least some instructions work with registers and use at least one
operand with the intention of returning a result, [0101] for at
least some of the instructions working with registers: [0102] a
part defining the functionality of the instruction, [0103] and a
part defining the expected chaining for the execution of the
instructions and including bits fields corresponding to: [0104] an
identification field of the instruction, [0105] and for each
operand of the instruction: [0106] a flag field, [0107] and an
expected identification field of the operand, [0108] for each
register belonging to the exploitation means and used by the
instructions set, a generated identification field in which is
automatically memorized the identification of the last instruction
which has returned its result in said register, [0109] as detection
means, means enabling, during the execution of an instruction, for
each operand, when the flag field imposes it, to check the equality
of the generated identification field corresponding to the register
used by said operand, and the expected identification field of the
origin of said operand, [0110] and as coercion means, means
enabling to modify the result of the instructions, if at least one
of the checked equalities is false.
[0111] According to a preferred embodiment, the process according
to the invention comprises: [0112] during the protection phase:
[0113] modifying the protected software: [0114] by choosing at
least one variable used in at least one chosen algorithmic
processing, which during the execution of the protected software,
partially defines the state of the protected software, [0115] by
modifying at least one chosen portion of the source of the
protected software, this modification being such that during the
execution of the protected software, at least one chosen variable
or at least one copy of chosen variable resides in the unit, [0116]
and by producing: [0117] the first object part of the protected
software, said first object part being such that during the
execution of the protected software, at least one portion of the
first execution part takes also into account that at least one
variable or at least one copy of variable resides in the unit,
[0118] and the second object part of the protected software, said
second object part being such that, after upload to the unit and
during the execution of the protected software, appears the second
execution part by means of which at least one chosen variable, or
at least one copy of chosen variable resides too in the unit,
[0119] and during the usage phase: [0120] in the presence of the
unit each time a portion of the first execution part imposes it,
using a variable or a copy of variable residing in the unit, so
that said portion is executed correctly and that, consequently, the
protected software is completely functional, [0121] and in the
absence of the unit, in spite of the request by a portion of the
first execution part to use a variable or a copy of variable
residing in the unit, not being able to fulfill said request
correctly, so that at least said portion is not executed correctly
and that, consequently the protected software is not completely
functional.
[0122] According to another preferred embodiment, the process
according to the invention comprises: [0123] during the protection
phase: [0124] defining: [0125] as a triggering command, an
instruction command, [0126] as a dependent function, an
instruction, [0127] as an order, at least one argument for a
triggering command, corresponding at least in part to the
information transmitted by the data processing system to the unit,
so as to trigger the execution of the corresponding dependent
function, [0128] a method of renaming of the orders enabling to
rename the orders so as to obtain triggering commands with renamed
orders, [0129] and restoring means designed to be used in the unit
during the usage phase, and enabling to restore the dependent
function to execute, from the renamed order, [0130] constructing
exploitation means enabling the unit to also implement the
restoring means, [0131] and modifying the protected software:
[0132] by choosing in the source of the protected software,
triggering commands, [0133] by modifying at least one chosen
portion of the source of the protected software by renaming the
orders of the chosen triggering commands, so as to conceal the
identity of the corresponding dependent functions, [0134] and by
producing: [0135] the first object part of the protected software,
said first object part being such that during the execution of the
protected software, the triggering commands with renamed orders are
executed, [0136] and the second object part of the protected
software containing the exploitation means also implementing the
restoring means, said second object part being such that, after
upload to the unit and during the execution of the protected
software, the identity of the dependent functions whose execution
is triggered by the first execution part is restored by means of
the second execution part, and the dependent functions are executed
by means of the second execution part, [0137] and during the usage
phase: [0138] in the presence of the unit and each time a
triggering command with renamed order, contained in a portion of
the first execution part imposes it, restoring in the unit, the
identity of the corresponding dependent function and executing it,
so that said portion is executed correctly and that, consequently,
the protected software is completely functional, [0139] and in the
absence of the unit, in spite of the request by a portion of the
first execution part, to trigger the execution of a dependent
function in the unit, not being able to fulfill said request
correctly, so that at least said portion is not executed correctly
and that, consequently, the protected software is not completely
functional.
[0140] According to a variant embodiment, the process according to
the invention comprises: [0141] during the protection phase: [0142]
defining for at least one dependent function, a family of dependent
functions algorithmically equivalent, but triggered by triggering
commands whose renamed orders are different, [0143] and modifying
the protected software: [0144] by choosing, in the source of the
protected software at least one triggering command with renamed
order, [0145] and by modifying at least one chosen portion of the
source of the protected software by replacing at least the renamed
order of one chosen triggering command with renamed order, with
another renamed order, triggering a dependent function of the same
family.
[0146] According to a variant embodiment, the process according to
the invention comprises: [0147] during the protection phase,
defining, for at least one dependent function, a family of
algorithmically equivalent dependent functions: [0148] by
concatenating a field of noise to the information defining the
functional part of the dependent function to execute in the unit,
[0149] or by using the identification field of the instruction and
the expected identification fields of the operands.
[0150] According to a variant embodiment, the process according to
the invention comprises: [0151] during the protection phase: [0152]
defining: [0153] as method of renaming of the orders, a ciphering
method to cipher the orders, [0154] and as restoring means, means
implementing a deciphering method to decipher the renamed orders
and thus restore the identity of the dependent functions to execute
in the unit.
[0155] According to another preferred embodiment, the process
according to the invention comprises: [0156] during the protection
phase: [0157] modifying the protected software: [0158] by choosing,
in the source of the protected software, at least one conditional
branch carried out in at least one chosen algorithmic processing,
[0159] by modifying at least one chosen portion of the source of
the protected software, this modification being such that during
the execution of the t protected software, the functionality of at
least one chosen conditional branch is executed, by means of the
second execution part, in the unit, [0160] and by producing: [0161]
the first object part of the protected software, said first object
part being such that during the execution of the protected
software, the functionality of at least one chosen conditional
branch is executed in the unit, [0162] and the second object part
of the protected software, said second object part being such that,
after upload to the unit and during the execution of the protected
software, appears the second execution part by means of which the
functionality of at least one chosen conditional branch is
executed, [0163] and during the usage phase: [0164] in the presence
of the unit and each time a portion of the first execution part
imposes it, executing the functionality of at least one conditional
branch in the unit, so that said portion is executed correctly and
that, consequently, the protected software is completely
functional, [0165] and in the absence of the unit and in spite of
the request by a portion of the first execution part to execute the
functionality of a conditional branch in the unit, not being able
to fulfill said request correctly, so that at least said portion is
not executed correctly and that consequently, the protected
software is not completely functional.
[0166] According to a variant embodiment, the process according to
the invention comprises, during the protection phase, modifying the
protected software: [0167] by choosing, in the source of the
protected software, at least one series of chosen conditional
branches, [0168] by modifying at least one chosen portion of the
source of the protected software, this modification being such that
during the execution of the protected software, the overall
functionality of at least one chosen series of conditional branches
is executed, by means of the second execution part, in the unit,
[0169] and by producing: [0170] the first object part of the
protected software, said first object part being such that during
the execution of the protected software, the functionality of at
least one chosen series of conditional branches is executed in the
unit, [0171] and the second object part of the protected software,
said second object part being such that, after upload to the unit
and during the execution of the protected software, appears the
second execution part by means of which the overall functionality
of at least one chosen series of conditional branches is
executed.
[0172] The process according to the invention thus enables to
protect usage of a software by using a processing and memorizing
unit which presents the characteristic of containing a part of the
software being executed. It follows that any derived version of the
software attempting to work without the processing and memorizing
unit imposes to recreate the part of the software contained in the
processing and memorizing unit during the execution, or else said
derived version of the software will not be completely
functional.
BRIEF DESCRIPTION OF THE DRAWINGS
[0173] Various other characteristics emerge from the description
made below in reference to the appended diagrams which show, as
non-limiting examples, embodiments and implementations of the
subject of the invention.
[0174] FIGS. 10 and 11 are functional blocks diagrams illustrating
the various representations of a software respectively not
protected and protected by the process in accordance with the
invention.
[0175] FIGS. 20 to 22 illustrate as examples, various embodiments
of an apparatus implementing the process in accordance with the
invention.
[0176] FIGS. 30 and 31 are functional blocks diagrams making
explicit the general principle of the process in accordance with
the invention.
[0177] FIGS. 40 to 43 are diagrams illustrating the protection
process according to the invention implementing the principle of
protection by variable.
[0178] FIGS. 70 to 74 are diagrams illustrating the protection
process according to the invention implementing the principle of
protection by detection and coercion.
[0179] FIGS. 80 to 85 are diagrams illustrating the protection
process according to the invention implementing the principle of
protection by par renaming.
[0180] FIGS. 90 to 92 are diagrams illustrating the protection
process according to the invention implementing the principle of
protection by conditional branch.
[0181] FIG. 100 is a diagram illustrating the different phases of
implementation of the subject of the invention.
[0182] FIG. 110 illustrates an embodiment of a system allowing the
implementation of the construction stage of the protection phase in
accordance with the invention.
[0183] FIG. 120 illustrates an embodiment of a pre-customization
unit used in the protection process in accordance with the
invention,
[0184] FIG. 130 illustrates an embodiment of a system allowing the
implementation of the tools making stage of the protection phase in
accordance with the invention.
[0185] FIG. 140 illustrates an embodiment of a system allowing the
implementation of the protection process according to the
invention.
[0186] FIG. 150 illustrates an embodiment of a customization unit
used in the protection process in accordance with the
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0187] In the rest of the description, the following definitions
will be used: [0188] A data processing system 3 is a system able to
execute a program. [0189] A processing and memorizing unit is a
unit able: [0190] to accept data provided by a data processing
system 3, [0191] to return data to the data processing system 3,
[0192] to store data at least partly in secret and to retain at
least a part of said data even if the unit is switched off, [0193]
and to carry out algorithmic processing on said data, part or all
of the result being secret. [0194] A unit 6 is a processing and
memorizing unit implementing the process according to the
invention. [0195] A blank unit 60 is a unit which does not
implement the process according to the invention, but which can
receive data transforming it into a unit 6. [0196] A pre-customized
unit 66 is a blank unit 60 which has received part of data enabling
it, after reception of supplementary data, to be transformed into a
unit 6. [0197] The upload of information to a blank unit 60 or a
pre-customized unit 66 corresponds to a transfer of information to
the blank unit 60 or the pre-customized unit 66, and to a storage
of said transferred information. The transfer can possibly include
a change of the information format. [0198] A variable, a function
or data contained in the data processing system 3 will be indicated
by an uppercase letter, while a variable, a function or data
contained in the unit 6 will be indicated by a lowercase letter.
[0199] A "protected software", is a software which has been
protected by at least one of the principles of protection
implemented by the process in accordance with the invention. [0200]
A "vulnerable software", is a software which has not been protected
by any principle of protection implemented by the process in
accordance with the invention. [0201] In the case where
differentiation between a vulnerable software and a protected
software is not important, the term "software" is used, [0202] A
software has various representations depending on the instant
considered in its life cycle: [0203] a source representation,
[0204] an object representation, [0205] a distribution, [0206] or a
dynamic representation. [0207] A source representation of a
software is understood as a representation which after
transformation, results in an object representation, A source
representation can offer different levels, from a conceptual
abstract level to a level executable directly by a data processing
system or a processing and memorizing unit. [0208] An object
representation of a software corresponds to a level of
representation which after transfer to a distribution and upload to
a data processing system or a processing and memorizing unit, can
be executed. It can be, for instance, a binary code, an interpreted
code, etc. [0209] A distribution is a physical or virtual support
containing the object representation, said distribution having to
be put at the user's disposal to enable them to use the software.
[0210] A dynamic representation corresponds to the execution of the
software from its distribution. [0211] A portion of a software
corresponds to some part of the software and can, for instance
correspond, to one or several consecutive or not instructions,
and/or one or several consecutive or not functional blocks, and/or
one or several functions, and/or one or several subprograms, and/or
one or several modules. A portion of a software can also correspond
to all of said software.
[0212] FIGS. 10 and 11 illustrate the various representations
respectively of a vulnerable software 2v in the general sense, and
of a protected software 2p protected according to the process in
accordance with the invention.
[0213] FIG. 10 illustrates various representations of a vulnerable
software 2v appearing during its life cycle, The vulnerable
software 2v can thus appear under any of the following
representations: [0214] a source representation 2vs, [0215] an
object representation 2vo, [0216] a distribution 2vd. Said
distribution can have commonly the form of a physical distribution
medium such as a CDROM or the form of files distributed through a
network (GSM, Internet, etc.), [0217] or a dynamic representation
2ve corresponding to the execution of the vulnerable software 2v on
a data processing system 3 of any known type, which classically
includes, at least one processor 4.
[0218] FIG. 11 illustrates various representations of a protected
software 2p appearing during its life cycle. The protected software
2p can thus appear under any of the following representations:
[0219] a source representation 2ps including a first source part
intended for the data processing system 3 and a second source part
intended for the unit 6, part of said source parts can commonly be
contained in common files, [0220] an object representation 2po
including a first object part 2pos intended for the data processing
system 3 and a second object part 2pou intended for the unit 6,
[0221] a distribution 2pd including: [0222] a first distribution
part 2pds containing the first object part 2pos, said first
distribution part 2pds being intended for the data processing
system 3 and which can commonly have the form of a physical
distribution medium such as a CDROM or the form of files
distributed through a network (GSM, Internet, etc.), [0223] and a
second distribution part 2pdu having the form: [0224] of at least
one pre-customized unit 66 to which a part of the second object
part 2pou has been uploaded and for which the user has to finish
the customization by uploading supplementary data so as to obtain a
unit 6, said supplementary data being obtained, for instance, by
download through a network, [0225] or of at least one unit 6 to
which the second object part 2pou has been uploaded, [0226] or a
dynamic representation 2pe corresponding to the execution of the
protected software 2p. Said dynamic representation 2pe includes a
first execution part 2pes which is executed in the data processing
system 3 and an second execution part 2peu which is executed in the
unit 6.
[0227] In the case where the differentiation between the different
representations of the protected software 2p is not important, the
expressions first part of the protected software and second part of
the protected software shall be used.
[0228] The implementation of the process according to the invention
in accordance with the dynamic representation of FIG. 11, uses an
apparatus 1p including a data processing system 3 linked up by a
link 5 to a unit 6. The data processing system 3 is of any type and
includes, classically, at least one processor 4. The data
processing system 3 can be a computer or be part, for instance, of
various machines, devices, fixed or mobile products, or vehicles in
the general sense. The link 5 can be realized in any possible way,
such as for instance a serial link, a USB bus, a radio link, an
optical link, a network link or a direct electric connection to a
circuit of data processing system 3, etc. It should be observed
that the unit 6 can possibly be physically located inside the same
integrated circuit than the processor 4 of the data processing
system 3. In this case, the unit 6 can be considered as a
co-processor in relation to the processor 4 of the data processing
system 3 and the link 5 is internal to the integrated circuit.
[0229] FIGS. 20 to 22 show in an illustrative and non-limiting
manner, various embodiments of the apparatus 1p allowing the
implementation of the protection process in accordance with the
invention.
[0230] In the embodiment illustrated in FIG. 20, the protection
apparatus 1p includes, as a data processing system 3, a computer
and, as a unit 6, a chip card 7 and its interface 8 commonly called
card reader. The computer 3 is linked up to the unit 6 by a link 5.
During the execution of the protected software 2p, the first
execution part 2pes which is executed in the computer 3 and the
second execution part 2peu which is executed in the chip card 7 and
its interface 8, must both be functional so that the protected
software 2p is completely functional.
[0231] In the embodiment illustrated in FIG. 21, the protection
apparatus 1p equips a product 9 in the general sense, including
various components 10 adapted to the function(s) assumed by such a
product 9. The protection apparatus 1p includes, on the one hand, a
data processing system 3 embedded in the product 9 and, on the
other hand, a unit 6 associated with the product 9. So that the
product 9 is completely functional, the protected software 2p, must
be completely functional. Thus, during the execution of the
protected software 2p, the first execution part 2pes which is
executed in the data processing system 3 and the second execution
part 2peu which is executed in the unit 6, must both be functional.
Said protected software 2p enables therefore indirectly, to protect
against unauthorized usage, the product 9 or one of its
functionalities. For instance, the product 9 can be an
installation, a system, a machine, a toy, a piece of domestic
appliances, a phone, etc.
[0232] In the embodiment illustrated in FIG. 22, the protection
apparatus 1p includes several computers, as well as part of a
communication network. The data processing system 3 is a first
computer linked up by a link 5 of network type, to a unit 6
constituted by a second computer. For the implementation of the
invention, the second computer 6 is used as a license server for a
protected software 2p. During the execution of the protected
software 2p, the first execution part 2pes which is executed in the
first computer 3 and the second execution part 2peu which is
executed in the second computer 6, must both be functional so that
the protected software 2p is completely functional.
[0233] FIG. 30 enables to make explicit more precisely, the
protection process in accordance with the invention. It should be
observed that a vulnerable software 2v, is considered as being
executed totally in a data processing system 3. On the other hand,
in the case of the implementation of a protected software 2p, the
data processing system 3 includes transfer means 12 linked up by
the link 5, to transfer means 13 being part of the unit 6 enabling
to establish communication between the first execution part 2pes
and the second execution part 2peu of the protected software
2p.
[0234] It must be considered that the transfer means 12, 13 are of
software and/or hardware nature and are capable of providing and,
possibly, optimizing the data communication between the data
processing system 3 and the unit 6. Said transfer means 12, 13 are
adapted to enable to have at one's disposal a protected software 2p
which is, preferably, independent from the type of link 5 used.
Said transfer means 12, 13 are not part of the subject of the
invention and are not described more precisely as they are well
known by the Man of art. The first part of the protected software
2p includes commands. During the execution of the protected
software 2p, the execution of said commands by the first execution
part 2pes enables the communication between the first execution
part 2pes and the second execution part 2peu. In the rest of the
description, said commands are represented by IN, OUT or TRIG.
[0235] As illustrated in FIG. 31, to allow the implementation of
the second execution part 2peu of the protected software 2p, the
unit 6 includes protection means 14. The protection means 14
include memorization means 15 and processing means 16.
[0236] For the sake of simplification in the rest of the
description, it is chosen to consider, during the execution of the
protected software 2p, the presence of the unit 6 or the absence of
the unit 6. In actual fact, a unit 6 providing protection means 14
not adapted to the execution of the second execution part 2peu of
the protected software 2p is also considered as missing, each time
the execution of the protected software 2p is not correct. In other
words: [0237] a unit 6 physically present and including protection
means 14 adapted to the execution of the second execution part 2peu
of the protected software 2p, is always considered as present,
[0238] a unit 6 physically present but including protection means
14 not adapted, i.e. not allowing the correct implementation of the
second execution part 2peu of the protected software 2p is
considered as present, when it works correctly, and as missing when
it does not work correctly, [0239] and a unit 6 physically missing
is always considered as missing,
[0240] In the case where the unit 6 is constituted by a chip card 7
and its interface 8, the transfer means 13 are split into two
parts, one being on the interface 8 and the other one being on the
chip card 7. In this embodiment, the absence of the chip card 7 is
considered as equivalent to the absence of the unit 6. In other
words, in the absence of the chip card 7 and/or its interface 8,
the protection means 14 are not accessible and do not enable the
execution of the second execution part 2peu of the protected
software 2p, so much so that the protected software 2p is not
completely functional.
[0241] In accordance with the invention, the protection process
aims at implementing a principle of protection, called by
<<detection and coercion>>, a description of which is
carried out in relation to FIGS. 70 to 74.
[0242] For the implementation of the principle of protection by
detection and coercion, are defined: [0243] at least one software
execution characteristic liable to be monitored at least in part in
the unit 6, [0244] at least one criterion to abide by for at least
one software execution characteristic, [0245] detection means 17 to
implement in the unit 6 and enabling to detect that at least one
software execution characteristic does not abide by at least one
associated criterion, [0246] and coercion means 18 to implement in
the unit 6 and enabling to inform the data processing system 3
and/or modify the execution of a software, when at least one
criterion is not abided by.
[0247] For the implementation of the principle of protection by
detection and coercion, are also constructed exploitation means
enabling to transform a blank unit 60 into a unit 6 implementing at
least the detection means 17 and the coercion means 18.
[0248] FIG. 70 illustrates the means necessary to the
implementation of this principle of protection by detection and
coercion. The unit 6 includes the detection means 17 and the
coercion means 18 belonging to the processing means 16. The
coercion means 18 are informed by the detection means 17 that a
criterion has not been abided by.
[0249] More precisely, the detection means 17 use information
coming from the transfer means 13 and/or from the memorization
means 15 and/or from the processing means 16, so as to monitor one
or several software execution characteristics. For each software
execution characteristic is set at least one criterion to abide
by.
[0250] In the case where it is detected that at least one software
execution characteristic does not abide by at least one criterion,
the detection means 17 inform the coercion means 18 of it. Said
coercion means 18 are adapted to modify, in the appropriate way,
the state of the unit 6.
[0251] For the implementation of the principle of protection by
detection and coercion, are also chosen: [0252] at least one
software execution characteristic to monitor, among the software
execution characteristics liable to be monitored, [0253] at least
one criterion to abide by for at least one chosen software
execution characteristic, [0254] in the source of the vulnerable
software 2vs, at least one algorithmic processing for which at
least one software execution characteristic is to be monitored,
[0255] a and in the source of the vulnerable software 2vs, at least
one portion containing at least one chosen algorithmic
processing.
[0256] At least one chosen portion of the source of the vulnerable
software 2vs is then modified, so as to obtain the source of the
protected software 2ps. This modification is such that, during the
execution of the protected software 2p, among others: [0257] at
least one portion of the first execution part 2pes, which is
executed in the data processing system 3, takes into account that
at least one chosen software execution characteristic is to be
monitored, at least in part in the unit 6, [0258] and the second
execution part 2peu, which is executed in the unit 6, monitors at
least in part, a chosen software execution characteristic.
[0259] During the execution of the protected software 2p, protected
by this principle of protection by detection and coercion, in the
presence of the unit 6: [0260] as long as all the criteria
corresponding to all the monitored execution characteristics of all
the modified portions of the protected software 2p are abided by,
said modified portions of the protected software 2p work nominally,
so that said protected software 2p works nominally, [0261] and if
at least one of the criteria corresponding to a monitored execution
characteristic of a portion of the protected software 2p is not
abided by, the data processing system 3 is informed of it and/or
the functioning of the portion of the protected software 2p is
modified, so that the functioning of the protected software 2p is
modified.
[0262] Naturally, in the absence of the unit 6, at least one
request by a portion of the first execution part 2pes of the
protected software 2p to use the unit 6 cannot be fulfilled
correctly so that at least said portion is not executed correctly
and that consequently the protected software 2p is not completely
functional.
[0263] For the implementation of the principle of protection by
detection and coercion, two types of software execution
characteristics are used preferentially.
[0264] The first type of software execution characteristic
corresponds to a variable of measurement of the execution of a
software and the second type corresponds to a profile of usage of a
software. Said two types of characteristics can be used
independently or in combination.
[0265] For the implementation of the principle of protection by
detection and coercion using, as execution characteristic, a
variable of measurement of software execution, are defined: [0266]
in the memorization means 15, the possibility to memorize at least
one variable of measurement used to quantify the usage of at least
one functionality of a software, [0267] in the detection means 17,
the possibility to monitor at least one threshold associated to
each variable of measurement, [0268] and actualization means
enabling to update each variable of measurement depending on the
usage of the functionality to which it is associated.
[0269] Are also constructed exploitation means implementing, in
addition to the detection means 17 and the coercion means 18, the
actualization means.
[0270] Are also chosen, in the source of the vulnerable software
2vs: [0271] at least one functionality of the vulnerable software
2v whose usage is liable to be monitored using a variable of
measurement, [0272] at least one variable of measurement used to
quantify the usage of said functionality, [0273] at least one
threshold associated to the variable of measurement corresponding
to a limit of usage of said functionality, [0274] and at least one
method of update of the variable of measurement depending on the
usage of said functionality,
[0275] The source of the vulnerable software 2vs is then modified,
so as to obtain the source of the protected software 2ps, this
modification being such that, during the execution of the protected
software 2p, the second execution 2peu: [0276] actualizes the
variable of measurement depending on the usage of said
functionality, [0277] and takes into account at least one threshold
crossing.
[0278] In other words, during the execution of the protected
software 2p, the variable of measurement is updated depending on
the usage of said functionality, and when the threshold is crossed,
the detection means 17 inform of it the coercion means 18 which
make an adapted decision to inform the data processing system 3
and/or to modify the processings carried out by the processing
means 16 enabling to modify the functioning of the portion of the
protected software 2p, so that the functioning of the protected
software 2p is modified.
[0279] For the implementation of a first preferred variant
embodiment of the principle of protection by detection and coercion
using, as characteristic, a variable of measurement, are defined:
[0280] for at least one variable of measurement, several associated
thresholds, [0281] and different coercion means corresponding to
each of said thresholds.
[0282] Are also chosen, in the source of the vulnerable software
2vs: [0283] at least one variable of measurement used to quantify
the usage of at least one functionality of the software and to
which must be associated several thresholds corresponding to
different limits of usage of said functionalities, [0284] and at
least two thresholds associated to the variable of measurement.
[0285] The source of the vulnerable software 2vs is then modified,
so as to obtain the source of the protected software 2ps, this
modification being such that, during the execution of the protected
software 2p, the second execution part 2peu: [0286] actualizes the
variable of measurement depending on the usage of said
functionality, [0287] and takes into account, differently, the
crossing of the various thresholds.
[0288] In other words, classically, during the execution of the
protected software 2p, when the first threshold is crossed, the
unit 6 informs the data processing system 3 enjoining the protected
software 2p not to use said functionality anymore. If the protected
software 2p carries on using said functionality, the second
threshold will potentially be crossed. In the case where the second
threshold is crossed, the coercion means 18 can make the chosen
functionality ineffective and/or make the protected software 2p
ineffective.
[0289] For the implementation of a second preferred variant
embodiment of the principle of protection by detection and coercion
using, as characteristic, a variable of measurement, are defined
refilling means enabling to credit at least one software
functionality monitored by a variable of measurement with at least
one additional usage.
[0290] Are also constructed exploitation means implementing, in
addition to the detection means 17, the coercion means 18 and the
actualization means, the refilling means.
[0291] Is also chosen, in the source of the vulnerable software
2vs, at least one variable of measurement used to limit the usage
of at least one functionality of the software and which must be
able to be credited with at least one additional usage.
[0292] The source of the vulnerable software 2vs is then modified,
so as to obtain the source of the protected software 2ps, this
modification being such that, during a phase called of refilling,
at least one additional usage of at least one functionality
corresponding to a chosen variable of measurement can be
credited.
[0293] Is carried out, during the phase of refilling, the
reactualization of at least one chosen variable of measurement
and/or of at least one associated threshold, so as to allow at
least one additional usage of the corresponding functionality. In
other words, it is possible, during the phase of refilling, to
credit additional usages of at least one functionality of the
protected software 2p.
[0294] For the implementation of the principle of protection by
detection and coercion using, as characteristic, a profile of
software usage, is defined as criterion to abide by for said
profile of usage, at least one feature of software execution.
[0295] Are also chosen, in the source of the vulnerable software
2vs: [0296] at least one profile of usage to monitor, [0297] and at
least one feature of execution by which at least one chosen profile
of usage must abide.
[0298] The source of the vulnerable software 2vs is then modified,
so as to obtain the source of the protected software 2ps, this
modification being such that, during the execution of the protected
software 2p, the second execution part 2peu abides by all the
chosen features of execution. In other words, the unit 6 itself
monitors the way the second execution part 2peu is executed and can
inform the data processing system 3 and/or modify the functioning
of the protected software 2p, in the case where at least one
feature of execution is not abided by.
[0299] During the execution of the protected software 2p, protected
by this principle, in the presence of the unit 6: [0300] as long as
all the features of execution of all the modified portions of the
protected software 2p are abided by, said modified portions of the
protected software 2p work nominally, so that said protected
software 2p works nominally, [0301] and if at least one feature of
execution of a portion of protected software 2p is not abided by,
the data processing system 3 is informed of it and/or the
functioning of the portion of the protected software 2p is
modified, so that the functioning of the protected software 2p is
modified.
[0302] The monitoring of different features of execution can be
considered, like for instance the monitoring of the presence of
instructions including a marker or the monitoring of the execution
chaining for at least one part of the instructions.
[0303] For the implementation of the principle of protection by
detection and coercion using as feature of execution to abide by,
the monitoring of the execution chaining for at least one part of
the instructions, are defined: [0304] an instructions set, whose
instructions are liable to be executed in the unit 6, [0305] a set
of instructions commands for said instructions set, said
instructions commands are liable to be executed in the data
processing system 3. The execution of each of said instructions
commands in the data processing system 3 triggers in the unit 6,
the execution of the corresponding instruction, [0306] detection
means 17 enabling to detect that the chaining of the instructions
does not correspond to the expected one, [0307] and coercion means
18 enabling to inform the data processing system 3 and/or to modify
the execution of a software when the chaining of the instructions
does not correspond to the expected one.
[0308] Are also constructed exploitation means enabling the unit 6
to also execute the instructions of the instructions set, the
execution of said instructions being triggered by the execution in
the data processing system 3 of the instructions commands.
[0309] Is also chosen, in the source of the vulnerable software
2vs, at least one algorithmic processing which must be remoted in
the unit 6 and for which the chaining of at least one part of the
instructions is to be monitored.
[0310] The source of the vulnerable software 2vs is then modified,
so as to obtain the source of the vulnerable software 2ps, this
modification being such that, during the execution of the protected
software 2p: [0311] the second execution part 2peu executes at
least the functionality of the chosen algorithmic processing,
[0312] the chosen algorithmic processing is split into
instructions, [0313] the chaining by which at least some of the
instructions must abide during their execution in the unit 6 is
specified, [0314] and the first execution part 2pes of the
protected software 2p executes instructions commands which trigger
the execution of the instructions in the unit 6.
[0315] During the execution of the protected software 2p, protected
by this principle, in the presence of the unit 6: [0316] as long as
the chaining of the instructions of all the modified portions of
the protected software 2p, executed in the unit 6 corresponds to
the expected one, said modified portions of the protected software
2p work nominally, so that said protected software 2p works
nominally, [0317] and if the chaining of the instructions of a
portion of the protected software 2p executed in the unit 6 does
not correspond to the expected one, the data processing system 3 is
informed of it and/or the functioning of the portion of protected
software 2p is modified, so that the functioning of the protected
software 2p is modified.
[0318] FIG. 71 illustrates an example of implementation of the
principle of protection by detection and coercion using, as feature
of execution to abide by the monitoring of the execution chaining
of a at least one part of the instructions, in the case where the
expected chaining is abided by.
[0319] The first execution part 2pes of the protected software 2p,
executed in the data processing system 3, executes instructions
commands CI.sub.i triggering, in the unit 6 the execution of the
instructions i.sub.i belonging to the instructions set. In said
instructions set, at least some of the instructions each include a
part defining the functionality of the instruction and a part
enabling to verify the expected chaining for the execution of the
instructions. In this example, the instructions commands CI.sub.i
are represented by TRIG(i.sub.i) and the expected chaining for the
execution of the instructions is i.sub.n, i.sub.n+1 and i.sub.n+2.
The execution in the unit 6, of the instruction i.sub.n gives the
result a and the execution of the instruction i.sub.n+1 gives the
result b. The instruction i.sub.n+2 uses as operand, the results a
and b of the instructions i.sub.n and i.sub.n+1 and its execution
gives the result c.
[0320] Taking into account that said chaining of the instructions
executed in the unit 6 corresponds to the expected one, it results
in a normal or nominal functioning of the protected software
2p.
[0321] FIG. 72 illustrates an example of implementation of the
principle of protection by detection and coercion using, as feature
of execution to abide by, the monitoring of the execution chaining
of at least one part of the instructions, in the case where the
expected chaining is not abided by.
[0322] According to this example, the expected chaining for the
execution of the instructions is still i.sub.n, i.sub.n+1, and
i.sub.n+2. However, the execution chaining is modified by the
replacement of the instruction i.sub.n with the instruction
i'.sub.n, so that the chaining actually executed is i'.sub.n,
i.sub.n+1 and i.sub.+2. The execution of the instruction i'.sub.n
gives the result a, i.e. the same result that the execution of the
instruction i.sub.n. However, at the latest during the execution of
the instruction i.sub.n+2, the detection means 17 detect that the
instruction i'.sub.n does not correspond to the expected
instruction to generate the result a used as operand of the
instruction i.sub.n+2 The detection means 17 inform of it the
coercion means 18 which modify accordingly, the functioning of the
instruction i.sub.n+2, so that the execution of the instruction
i.sub.n+2 gives the result c' which can be different than C.
Naturally, if the execution of the instruction i'.sub.n gives a
result a' different from the result a of the instruction i.sub.n,
it is clear that the result of the instruction i.sub.n+2 can also
be different from c.
[0323] In as much as the execution chaining of the instructions
executed in the unit 6 does not correspond to the expected one, a
modification of the functioning of the protected software 2p can
therefore be obtained.
[0324] FIGS. 73 and 74 illustrates a preferred variant embodiment
of the principle of protection by detection and coercion using, as
feature of execution to abide by, the monitoring of the execution
chaining of at least one part of the instructions. According to
this preferred variant, is defined an instructions set whose at
least some instructions work with registers and use at least one
operand with the intention of returning a result
[0325] As illustrated in FIG. 73, are defined for at least some of
the instructions working with registers, a part PF defining the
functionality of the instruction and a part PE defining the
expected chaining for the execution of the instructions. The part
PF corresponds to the operation code known by the Man of art. The
part PE defining the expected chaining, includes bits fields
corresponding to: [0326] an identification field of the instruction
CII, [0327] and for each operand k of the instruction, with k
varying from 1 to K, and K number of operands of the instruction:
[0328] a flag field CD.sub.k, indicating whether or not it is
appropriate to verify the origin of the operand k, [0329] and an
expected identification field CIP.sub.k of the operand, indicating
the expected identity of the instruction which has generated the
contents of the operand k.
[0330] As illustrated in FIG. 74, the instructions set includes V
registers belonging to the processing means 16, each register being
named R.sub.v, with v varying from 1 to V. For each register
R.sub.v, are defined two fields, namely: [0331] a functional field
CF.sub.v, known by the Man of art and enabling to store the result
of the execution of the instructions, [0332] and a generated
identification field CIG.sub.v, enabling to memorize the identity
of the instruction which has generated the contents of the
functional field CF.sub.v.
[0333] Said generated identification field CIG.sub.v is
automatically updated with the contents of the identification field
of the instruction CII which has generated the functional field
CF.sub.v. Said generated identification field CIG.sub.v is neither
accessible, nor modifiable by any of the instructions and is solely
used for the detection means 17.
[0334] During the execution of an instruction, the detection means
17 carry out for each operand k the following operations: [0335]
the flag field CD.sub.k is read, [0336] if the flag field CD.sub.k
imposes it, the expected identification field CIP.sub.k and the
generated identification field CIG.sub.v corresponding to the
register used by the operand k are both read, [0337] the equality
of the two fields CIP.sub.k and CIG.sub.v is checked, [0338] and if
the equality is false, the detection means 17 consider that the
execution chaining of the instructions is not abided by.
[0339] The coercion means 18 enable to modify the result of the
instructions when the detection means 17 has informed them of an
instructions chaining not abided by. A preferred embodiment is
carried out by modifying the functional part PF of the instruction
currently executed or the functional part PF of subsequent
instructions.
[0340] According to another advantageous characteristic of the
invention, the protection process aims at implementing a principle
of protection called by <<variable>> a description of
which is carried out in relation to FIGS. 40 to 43.
[0341] For the implementation of the principle of protection by
variable, is chosen in the source of the vulnerable software 2vs at
least one variable which, during the execution of the vulnerable
software 2v, partially defines its state. By state of a software,
must be understood the set of pieces of information, at a given
moment, necessary to the complete execution of said software, so
much so that the absence of such a chosen variable prejudices the
complete execution of said software. Is also chosen at least one
portion of the source of the vulnerable software 2vs containing at
least one chosen variable.
[0342] At least one chosen portion of the source of the vulnerable
software 2vs is then modified, so as to obtain the source of the
protected software 2ps. This modification is such that during the
execution of the protected software 2p, at least one portion of the
first execution part 2pes which is executed in the data processing
system 3, takes into account that at least one chosen variable or
at least one copy of chosen variable resides in the unit 6.
[0343] FIG. 40 illustrates an example of execution of a vulnerable
software 2v. In this example, during the execution of the
vulnerable software 2v in the data processing system 3, appear:
[0344] at time instant t.sub.1, the assignment of the data X to the
variable V.sub.1, represented by V.sub.1.rarw.X, [0345] at time
instant t.sub.2, the assignment of the value of the variable
V.sub.1 to the variable Y, represented by Y.rarw.V.sub.1, [0346]
and at time instant t.sub.3, the assignment of the value of the
variable V.sub.1 to the variable Z, represented by
Z.rarw.V.sub.1.
[0347] FIG. 41 illustrates an example of a first form of
implementation of the invention for which the variable resides in
the unit 6. In this example, during the execution in the data
processing system 3 of the first execution part 2pes of the
protected software 2p, and in presence of the unit 6, appear:
[0348] at time instant t.sub.1, the execution of a transfer command
triggering the transfer of the data X from the data processing
system 3 to the variable v.sub.1, located in the memorization means
15 of the unit 6, said transfer command being represented by
OUT(v.sub.1, X) and corresponding in the end to the assignment of
the data X to the variable v.sub.1, [0349] at time instant t.sub.2,
the execution of a transfer command triggering the transfer of the
value of the variable v.sub.1 residing in the unit 6 to the data
processing system 3 so as to assign it to the variable Y, said
transfer command being represented by IN(v.sub.1) and corresponding
in the end to the assignment of the value of the variable v.sub.1
to the variable Y, [0350] and at time instant t.sub.3, the
execution of a transfer command triggering the transfer of the
value of the variable v.sub.1 residing in the unit 6 to the data
processing system 3 so as to assign it to the variable Z, said
transfer command being represented by IN(v.sub.1) and corresponding
in the end to the assignment of the value of the variable v.sub.1
to the variable Z.
[0351] It should be observed that during the execution of the
protected software 2p, at least one variable resides in the unit 6.
Thus, when a portion of the first execution part 2pes of the
protected software 2p imposes it, and in the presence of the unit
6, the value of said variable residing in the unit 6 is transferred
to the data processing system 3 to be used by the first execution
part 2pes of the protected software 2p, so much so that said
portion is executed correctly and that, consequently, the protected
software 2p is completely functional.
[0352] FIG. 42 illustrates an example of a second form of
implementation of the invention for which a copy of the variable
resides in the unit 6. In this example, during the execution in the
data processing system 3 of the first execution part 2pes of the
protected software 2p, and in the presence of the unit 6, appear:
[0353] at time instant t.sub.1, the assignment of the data X to the
variable V.sub.1 located in the data processing system 3, as well
as the execution of a transfer command triggering the transfer of
the data X from the data processing system 3 to the variable
v.sub.1 located in the memorization means 15 of the unit 6, said
transfer command being represented by OUT(v.sub.1, X), [0354] at
time instant t.sub.2, the assignment of the value of the variable
V.sub.1 to the variable Y, [0355] and at time instant t.sub.3, the
execution of a transfer command triggering the transfer of the
value of the variable v.sub.1 residing in the unit 6 to the data
processing system 3 so as to affect it to the variable Z, said
transfer command being represented by IN(v.sub.1).
[0356] It should be observed that during the execution of the
protected software 2p, at least one copy of a variable resides in
the unit 6. Thus, when a portion of the first execution part 2pes
of the protected software 2p, imposes it, and in the presence of
the unit 6, the value of said copy of variable residing in the unit
6 is transferred to the data processing system 3 to be used by the
first execution part 2pes of the protected software 2p, so much so
that said portion is executed correctly and that, consequently, the
protected software 2p is completely functional.
[0357] FIG. 43 illustrates an example of attempt of execution of
the protected software 2p, when the unit 6 is missing. In this
example, during the execution in the data processing system 3 of
the first execution part 2pes of the protected software 2p: [0358]
at time instant t.sub.1 the execution of the transfer command
OUT(v.sub.1, X) cannot trigger the transfer of the data X to the
variable v.sub.1, taking into account the absence of the unit 6,
[0359] at time instant t.sub.2, the execution of the transfer
command IN(v.sub.1) cannot trigger the transfer of the value of the
variable v.sub.1, to the data processing system 3, taking into
account the absence of the unit 6, [0360] and at time instant
t.sub.3, the execution of the transfer command IN(v.sub.1) cannot
trigger the transfer of the value of the variable v.sub.1 to the
data processing system 3, taking into account the absence of the
unit 6.
[0361] It therefore appears that in the absence of the unit 6, at
least one request by a portion of the first execution part 2pes to
use a variable or a copy of variable residing in the unit 6, cannot
be fulfilled correctly, so that at least said portion is not
executed correctly and that, consequently, the protected software
2p is not completely functional.
[0362] It should be observed that the data transfers between the
data processing system 3 and the unit 6 illustrated in the previous
examples use only simple assignments but that the Man of art will
know how to combine them with other operations to obtain complex
operations such as for instance OUT(v1, 2* X+3) or Z.rarw.(5*
v1+v2).
[0363] According to another advantageous characteristic of the
invention, the protection process aims at implementing a principle
of protection, called by << renaming>> a description of
which is carried out in relation to FIGS. 80 to 85.
[0364] For the implementation of the principle of protection by
renaming, are defined: [0365] a set of dependent functions, whose
dependent functions are liable to be executed, by means of the
second execution part 2peu, in the unit 6, and possibly to transfer
data between the data processing system 3 and the unit 6, said set
of dependent functions can be finite or infinite, [0366] a set of
triggering commands for said dependent functions, said triggering
commands being liable to be executed in the data processing system
3 and to trigger in the unit 6, the execution of corresponding
dependent functions, [0367] for each triggering command, an order
corresponding at least in part to the information transmitted by
the first execution part 2pes, to the second execution part 2peu,
so as to trigger the execution of the corresponding dependent
function, said order having the form of at least one argument of
the triggering command, [0368] a method of renaming of the orders
designed to be used during the modification of the vulnerable
software 2v, such a method enabling to rename the orders so as to
obtain triggering commands with renamed orders enabling to conceal
the identity of the corresponding dependent functions, [0369] and
restoring means 20 designed to be used in the unit 6 during the
usage phase and enabling to restore the initial order, from the
renamed order, so as to restore the dependent function to
execute.
[0370] For the implementation of the principle of protection by
renaming, are also constructed exploitation means enabling to
transform a blank unit 60 into a unit 6 implementing at least the
restoring means 20.
[0371] For the implementation of the principle of protection by
renaming, are also chosen, in the source of the vulnerable software
2vs: [0372] at least one algorithmic processing using at least one
operand and returning at least one result, [0373] and at least one
portion of the source of the vulnerable software 2vs, containing at
least one chosen algorithmic processing.
[0374] The source of the vulnerable software 2vs is then modified,
so as to obtain the source of the protected software 2ps. This
modification is such that, among others: [0375] during the
execution of the protected software 2p, at least one portion of the
first execution part 2pes, which is executed in the data processing
system 3, takes into account that the functionality of at least one
chosen algorithmic processing is executed in the unit 6, [0376]
during the execution of the protected software 2p, the second
execution part 2peu, which is executed in the unit 6, executes at
least the functionality of at least one chosen algorithmic
processing, [0377] each chosen algorithmic processing is split so
that during the execution of the protected software 2p, each chosen
algorithmic processing is executed, by means of the second
execution part 2peu, using dependent functions.
[0378] Preferably, each chosen algorithmic processing is split into
dependent functions fd.sub.n (with n varying from 1 to N), namely:
[0379] possibly one or several dependent functions enabling the
placing of one or several operands at the unit 6's disposal, [0380]
dependent functions, some of which use the operand(s) and execute
in combination the functionality of the chosen algorithmic
processing, using said operand(s), [0381] and possibly, one or
several dependent functions enabling the placing by the unit 6, at
the data processing system 3's disposal of the result of the chosen
algorithmic processing, [0382] during the execution of the
protected software 2p, the second execution part 2peu executes the
dependent functions fd.sub.n, [0383] during the execution of the
protected software 2p, the dependent functions are triggered by
triggering commands with renamed orders, [0384] and a sequence of
the triggering commands is chosen among the set of sequences
allowing the execution of the protected software 2p.
[0385] The first execution part 2pes of the protected software 2p,
executed in the data processing system 3, executes triggering
commands with renamed orders transferring renamed orders to the
unit 6, and triggering in the unit 6 the restoring by means of the
restoring means 20, of the orders, and then the execution by means
of the second execution part 2peu, of each of the previously
defined dependent functions fd.sub.n.
[0386] In other words, the principle of protection by renaming is
carried out by renaming the orders of the triggering commands, so
as to obtain triggering commands with renamed orders whose
execution in the data processing system 3, triggers in the unit 6,
the execution of the dependent functions which would have been
triggered by the triggering commands with not-renamed orders,
without however the examination of the protected software 2p
enabling to determine the identity of the executed dependent
functions.
[0387] FIG. 80 illustrates an example of execution of a vulnerable
software 2v. In this example, appears during the execution of the
vulnerable software 2v in the data processing system 3, at a
certain time instant, the calculation of Z.rarw.F(X, Y)
corresponding to the assignment to a variable Z of the result of an
algorithmic processing represented by a function F and using the
operands X and Y.
[0388] FIGS. 81 and 82 illustrate an example of implementation of
the invention.
[0389] FIG. 81 illustrates the partial implementation of the
invention. In this example, during the execution in the data
processing system 3 of the first execution part 2pes of the
protected software 2p and in the presence of the unit 6, appear:
[0390] a at time instants t.sub.1, t.sub.2, the execution of the
triggering commands CD.sub.1, CD.sub.2 triggering in the unit 6,
the execution by means of the second execution part 2peu, of the
corresponding dependent functions fd.sub.1, fd.sub.2 which provide
the transfer of data X, Y from the data processing system 3 to the
memorization zones respectively x, y located in the memorization
means 15 of the unit 6, said triggering commands CD.sub.1, CD.sub.2
being represented respectively by OUT(X, X), OUT(y, Y), [0391] at
time instants t.sub.3 to t.sub.N-1, the execution of the triggering
commands CD.sub.3 to CD.sub.N-1, triggering in the unit 6, the
execution by means of the second execution part 2peu, of the
corresponding dependent functions fd.sub.3 to fd.sub.N-1, said
triggering commands CD.sub.3 to CD.sub.N-1, being represented
respectively, by TRIG(fd.sub.3) to TRIG(fd.sub.N-1). The series of
dependent functions fd.sub.3 to fd.sub.N-1 executed in combination
is algorithmically equivalent to the function F. More precisely,
the execution of said triggering commands leads to the execution in
the unit 6, of the dependent functions fd.sub.3 to fd.sub.N-1 which
use the contents of the memorization zones x, y and return the
result in a memorization zone z of the unit 6, [0392] and at time
instant t.sub.N, the execution of a triggering command CD.sub.N
triggering in the unit 6, the execution by means of the second
execution part 2peu, of the dependent function fd.sub.N providing
the transfer of the result of the algorithmic processing contained
in the memorization zone z of the unit 6 to the data processing
system 3, so as to assign it to the variable Z, said command being
represented by IN(z).
[0393] In this example, to completely implement the invention, are
chosen as orders, the first argument of the triggering commands OUT
and the argument of the triggering commands TRIG and IN. The orders
chosen in this way are renamed using the method of renaming of the
orders. In this manner, the orders of the triggering commands
CD.sub.1 to CD.sub.N i.e, x, y, fd.sub.3, fd.sub.N-1, z are renamed
so as to obtain respectively R(x), R(y), R(fd.sub.3) . . . ,
R(fd.sub.N-1), R(z).
[0394] FIG. 82 illustrates the complete implementation of the
invention. In this example, during the execution in the data
processing system 3, of the first execution part 2pes of the
protected software 2p, and in the presence of the unit 6, appear:
[0395] at time instants t.sub.1, t.sub.2, the execution of the
triggering commands with renamed orders CDCR.sub.1, CDCR.sub.2,
transferring to the unit 6, the renamed orders R(x), R(y) as well
as the data X, Y triggering in the unit 6 the restoring by means of
the restoring means 20, of the renamed orders to restore the orders
i.e. the identity of the memorization zones x, y, and then the
execution by means of the second execution part 2peu, of the
corresponding dependent functions fd.sub.1, fd.sub.2 which provide
the transfer of the data X, Y from the data processing system 3 to
the memorization zones respectively x, y located in the
memorization means 15 of the unit 6, said triggering commands with
renamed orders CDCR.sub.1, CDCR.sub.2 being represented
respectively by OUT (R(x), X), OUT (R(y), Y), [0396] at time
instants t.sub.3 to t.sub.N-1, the execution of the triggering
commands with renamed orders CDCR.sub.3 to CDCR.sub.N-1,
transferring to the unit 6, the renamed orders R(fd.sub.3) to
R(fd.sub.N-1), triggering in the unit 6 the restoring by means of
the restoring means 20, of the orders, i.e. fd.sub.3 to fd.sub.N-1,
and then the execution by means of the second execution part 2peu,
of the dependent functions fd.sub.3 to fd.sub.N-1, said triggering
commands with renamed orders ClCR.sub.3 to CDCR.sub.N-1 being
represented respectively by TRIG (R(fd.sub.3)) to TRIG
R(fd.sub.N-1)), [0397] and at time instant t.sub.N, the execution
of the triggering command with renamed order CDCR.sub.N
transferring to the unit 6, the renamed order R(z) triggering in
the unit 6 the restoring by means of restoring means 20, of the
order i.e. the identity of the memorization zone z, and then the
execution by means of the second execution part 2peu, of the
dependent function fd.sub.N providing the transfer of the result of
the algorithmic processing contained in the memorization zone z of
the unit 6 to the data processing system 3, so as to assign it to
the variable Z, said triggering command with renamed order
CDCR.sub.N being represented by IN (R(z)).
[0398] In the illustrated example, the triggering commands with
renamed orders 1 to N are executed successively. It should be
observed that two improvements can be effected: [0399] The first
improvement concerns the case where several algorithmic processings
are remoted to the unit 6 and at least the result of one
algorithmic processing is used by another algorithmic processing.
In this case, some triggering commands with renamed orders used for
the transfer, can possibly be removed. [0400] The second
improvement aims at opting for a pertinent sequence of the
triggering commands with renamed orders among the set of sequences
allowing the execution of the protected software 2p. In this
respect, it is preferable to choose a sequence of the triggering
commands with renamed orders which dissociate temporally the
execution of the dependent functions, by intercalating, between
them portions of code executed in the data processing system 3 and
including or not triggering commands with renamed orders used of
the determination of other data. FIGS. 83 and 84 illustrate the
principle of such an embodiment.
[0401] FIG. 83 shows an example of execution of a vulnerable
software 2v. In this example, appears, during the execution of the
vulnerable software 2v, in the data processing system 3, the
execution of two algorithmic processings leading to the
determination of Z and Z', such as Z.rarw.F (X, Y) and
Z'.rarw.F'(X', Y').
[0402] FIG. 84 illustrates an example of implementation of the
process according to the invention for which the two algorithmic
proccesings chosen in FIG. 83 are remoted to the unit 6. According
to such an example, during the execution in the data processing
system 3 of the first execution part 2pes of the protected software
2p and in the presence of the unit 6, appear, as explained above,
the execution of the triggering commands with renamed orders
CDCR.sub.1 to CDCR.sub.N corresponding to the determination of Z
and the execution of the triggering commands with renamed orders
CDCR'.sub.1 to CDCR'.sub.M corresponding to the determination of
Z'. As illustrated, the triggering commands with renamed orders
CDCR.sub.1 to CDCR.sub.N are not executed consecutively, inasmuch
as the triggering commands with renamed orders CDCR'.sub.1 to
CDCR'.sub.M as well as other portions of code are intercalated. In
the example, the following sequence is thus carried out:
CDCR.sub.1, portion of intercalated code, CDCR'.sub.1, CDCR.sub.2,
portion of intercalated code, CDCR'.sub.2, CDCR'.sub.3, portion of
intercalated code, CDCR'.sub.4, CDCR.sub.3, CDCR.sub.4, . . . ,
CDCR.sub.N, CDCR'.sub.M.
[0403] It should be observed that, during the execution of a
portion of the first execution part 2pes of the protected software
2p, the triggering commands with renamed orders executed in the
data processing system 3, trigger in the unit 6 the restoring of
the identity of the corresponding dependent functions and then
their execution. Thus, it appears that in the presence of the unit
6, said portion is executed correctly and that, consequently, the
protected software 2p is completely functional,
[0404] FIG. 85 illustrates an example of an attempt of execution of
the protected software 2p, when the unit 6 is missing. In this
example, during the execution in the data processing system 3 of
the first execution part 2pes of the protected software 2p, at
every time instant, the execution of a triggering command with
renamed order can trigger neither the restoring of the order nor
the execution of the corresponding dependent function, because of
the absence of the unit 6. The value to assign to the variable Z
cannot therefore be determined correctly.
[0405] It therefore appears, that in the absence of the unit 6, at
least one request by a portion of the first execution part 2pes of
the protected software 2p, to trigger the restoring of an order and
the execution of a dependent function in the unit 6 cannot be
fulfilled correctly, so that at least said portion is not executed
correctly and that, consequently, the protected software 2p is not
completely functional.
[0406] Thanks to this principle of protection by renaming, the
examination in the protected software 2p of the triggering commands
with renamed orders does not enable to determine the identity of
the dependent functions which have to be executed in the unit 6. It
should be observed that the renaming of the orders is carried out
during the modification of the vulnerable 2v to a protected
software 2p.
[0407] According to a variant of the principle of protection by
renaming, is defined for at least one dependent function, a family
of dependent functions algorithmically equivalent but triggered by
different triggering commands with renamed orders. According to
this variant, for at least one algorithmic processing using
dependent functions, said algorithmic processing is split into
dependent functions which for at least one of them is replaced with
a dependent function of the same family instead of keeping several
occurrences of the same dependent function. To this end, triggering
commands with renamed orders are modified to take into account the
replacement of dependent functions with dependent functions of the
same family. In other words, two dependent functions of the same
family have different orders and consequently different triggering
commands with renamed orders and, it is not possible, by examining
the protected software 2p, to discover that the dependent functions
called are algorithmically equivalent.
[0408] According to a first preferred embodiment of the variant of
the principle of protection by renaming, is defined for at least
one dependent function, a family of algorithmically equivalent
dependent functions, by concatenating a noise field to the
information defining the functional part of the dependent function
to execute in the unit 6.
[0409] According to a second preferred embodiment of the variant of
the principle of protection by renaming, is defined for at least
one dependent function, a family of algorithmically equivalent
dependent functions by using identification fields.
[0410] According to a preferred variant embodiment of the principle
of protection by renaming, is defined as method of renaming of the
orders a ciphering method enabling to cipher the orders to
transform them into renamed orders. Remember that the renaming of
the orders is carried out during the phase of protection P. For
this preferred variant, the restoring means 20 are means
implementing a deciphering method enabling to decipher the renamed
orders and thus to restore the identity of the dependent functions
to execute in the unit 6. Said restoring means are implemented in
the unit 6 and can be of software or hardware nature. Said
restoring means 20 are appealed to during the usage phase U each
time a triggering command with renamed order is executed in the
data processing system 3 with the intention of triggering in the
unit 6, the execution of a dependent function.
[0411] According to another advantageous characteristic of the
invention, the protection process aims at implementing a principle
of protection called by (<<conditional branch >> a
description of which is carried out in relation to FIGS. 90 to
92.
[0412] For the implementation of the principle of protection by
conditional branch, is chosen in the source of the vulnerable
software 2vs, at least one conditional branch BC. Is also chosen at
least one portion of the source of the vulnerable software 2vs
containing at least one chosen conditional branch BC.
[0413] At least one chosen portion of the source of the vulnerable
software 2vs is then modified, so as to obtain the source of the
protected software 2ps. This modification is such that, during the
execution of the protected software 2p, among others: [0414] at
least one portion of the first execution part 2pes, which is
executed in the data processing system 3, takes into account that
the functionality of at least one chosen conditional branch BC is
executed in the unit 6, [0415] and the second execution part 2peu,
which is executed in the unit 6, executes at least the
functionality of at least one chosen conditional branch BC and puts
at the data processing system 3's disposal, a piece of information
enabling the first execution part 2pes, to carry on its execution
at the chosen spot.
[0416] The first execution part 2pes of the protected software 2p,
executed in the data processing system 3, executes conditional
branches commands, triggering in the unit 6, the execution by means
of the second execution part 2peu, of remoted conditional branches
be whose functionality is equivalent to the functionality of the
chosen conditional branches BC.
[0417] FIG. 90 illustrates an example of execution of a vulnerable
software 2v. In this example, appears, during the execution of the
vulnerable software 2v in the data processing system 3 at a certain
time instant, a conditional branch BC indicating to the vulnerable
software 2v the spot where to carry on its execution, i.e, one of
the three possible spots B.sub.1, B.sub.2 or B.sub.3. It must be
understood that the conditional branch BC takes the decision to
carry on the execution of the software at spot B.sub.1, B.sub.2 or
B.sub.3.
[0418] FIG. 91 illustrates an example of implementation of the
invention for which the conditional branch chosen to be remoted to
the unit 6, corresponds to the conditional branch BC. In this
example, during the execution in the data processing system 3 of
the first execution part 2pes of the protected software 2p and in
the presence of the unit 6, appear: [0419] at time instant t.sub.1,
the execution of the conditional branch command CBC.sub.1,
triggering in the unit 6, the execution by means of the second
execution part 2peu, of the remoted conditional branch be
algorithmically equivalent to the conditional branch BC, said
conditional branch command CBC.sub.1, being represented by
TRIG(be), [0420] and at time instant t.sub.2, the transfer from the
unit 6 to the data processing system 3, of the information enabling
the first execution part 2pes, to carry on its execution at the
chosen spot, i.e. the spot B.sub.1 B.sub.2 or B.sub.3.
[0421] It should be observed that during the execution of a portion
of the first execution part 2pes of the protected software 2p, the
conditional branches commands executed in the data processing
system 3 trigger the execution of the corresponding remoted
conditional branches in the unit 6. Thus, it appears, that in the
presence of the unit 6, said portion is executed correctly and
that, consequently, the protected software 2p is completely
functional.
[0422] FIG. 92 illustrates an example of an attempt of execution of
the protected software 2p, when the unit 6 is missing In this
example, during the execution in the data processing system 3 of
the first execution part 2pes of the protected software 2p: [0423]
at time instant t.sub.1, the execution of the conditional branch
command CBC.sub.1, cannot trigger the execution of the remoted
conditional branch be, taking into account the absence of the unit
6, [0424] and at time instant t.sub.2, the transfer of the piece of
information enabling the first execution part 2pes to carry on at
the chosen spot fails taking into account the absence of the unit
6.
[0425] It therefore appears that in the absence of the unit 6, at
least one request by a portion of the first execution part 2pes to
trigger the execution of a remoted conditional branch in the unit
6, cannot be fulfilled correctly, so that at least said portion is
not executed correctly and that, consequently, the protected
software 2p is not completely functional.
[0426] In the previous description in relation to FIGS. 90 to 92,
the subject of the invention aims at remoting in the unit 6, a
conditional branch. Naturally, a preferred embodiment of the
invention can be carried out by remoting in the unit 6, a series of
conditional branches whose overall functionality is equivalent to
all the functionalities of the conditional branches which have been
remoted. The execution of the overall functionality of said series
of remoted conditional branches leads to the placing at the data
processing system 3's disposal of a piece of information enabling
the first execution part 2pes of the protected software 2p to carry
on its execution at the chosen spot.
[0427] In the previous description in relation to FIGS. 40 to 92,
four different principles of software protection have been made
explicit generally speaking independently of one another. The
protection process in accordance with the invention, is implemented
by using the principle of protection by detection and coercion,
possibly combined with one or several other principles of
protection. In the case where the principle of protection by
detection and coercion is complemented by the implementation of at
least another principle of protection, the principle of protection
by detection and coercion is advantageously complemented by the
principle of protection by variable and/or the principle of
protection by renaming and/or the principle of protection by
conditional branch.
[0428] And when the principle of protection by renaming is also
implemented, it can be complemented in its turn by the principle of
protection by conditional branch.
[0429] According to the preferred variant embodiment, the principle
of protection by detection and coercion is complemented by the
principle of protection by variable and by the principle of
protection by renaming, complemented by the principle of protection
by conditional branch.
[0430] In the case where a principle of protection is applied, in
complement to the principle of protection by detection and
coercion, its previously carried out description must include, to
take into account its combined implementation, the following
modifications: [0431] the notion of vulnerable software must be
understood as software vulnerable towards the principle of
protection being described, Thus, in the case where a principle of
protection has already been applied to the vulnerable software, the
expression "vulnerable software" must be interpreted by the reader
as the expression "software protected by the principle(s) of
protection already applied"; [0432] the notion of protected
software must be understood as software protected towards the
principle of protection being described. Thus, in the case where a
principle of protection has already been applied, the expression
"protected software" must be interpreted by the reader as the
expression "new version of the protected software"; [0433] and the
choice(s) made for the implementation of the principle of
protection being described must take into account the choice(s)
made for the implementation of the principle(s) of protection
already applied.
[0434] The rest of the description enables to have a better
understanding of the implementation of the protection process in
accordance with the invention. This protection process according to
the invention is composed, as shown more precisely in FIG. 100:
[0435] first, of a protection phase P during which a vulnerable
software 2v is modified to become a protected software 2p, [0436]
then, of a usage phase U during which the protected software 2p is
used. During this usage phase U: [0437] in the presence of the unit
6 and each time a portion of the first execution part 2pes executed
in the data processing system 3 imposes it, an imposed
functionality is executed in the unit 6, so that said portion is
executed correctly and that, consequently, the protected software
2p is completely functional, [0438] in the absence of the unit 6
and in spite of the request by a portion of the first execution
part 2pes to execute a functionality in the unit 6, said request
cannot be fulfilled correctly, so that at least said portion is not
executed correctly and that consequently, the protected software 2p
is not completely functional, [0439] and possibly of a phase of
refilling R during which is credited at least one additional usage
of a functionality protected by the implementation of the second
preferred variant embodiment of the principle of protection by
detection and coercion using as characteristic, a variable of
measurement.
[0440] The protection phase P can be split into two protection
sub-phases P.sub.1 and P.sub.2. The first one, called prior
protection sub-phase P.sub.1, takes place independently of the
vulnerable software 2v to protect. The second one, called
subsequent protection sub-phase P.sub.2 is dependent of the
vulnerable software 2v to protect, It should be observed that the
prior protection sub-phase P.sub.1 and the subsequent protection
sub-phase P.sub.2 can be carried out advantageously by two
different persons or two different teams. For instance, the prior
protection sub-phase P.sub.1 can be carried out by a person or a
company providing the development of software protection systems,
while the subsequent protection sub-phase P.sub.2 can be carried
out by a person or a company providing the development of software
requiring to be protected. Naturally, it is clear that the prior
protection sub-phase P.sub.1 and the subsequent protection
sub-phase P.sub.2 can also be carried out by the same 3 person or
team.
[0441] The prior protection sub-phase P.sub.1 is composed of
several stages S.sub.11, . . . , S.sub.11 for each of which various
tasks or jobs are to be carried out.
[0442] The first stage of this prior protection sub-phase P.sub.1
is called "definitions stage S.sub.11,". During this definitions
stage S.sub.11: [0443] are chosen: [0444] the type of the unit 6.
As an illustrative example, can be chosen as unit 6, a chip card
reader 8 and the chip card 7 associated to the reader, [0445] and
the transfer means 12, 13 designed to be implemented respectively
in the data processing system 3 and in the unit 6, during the usage
phase U and capable of providing the transfer of data between the
data processing system 3 and the unit 6, [0446] are defined: [0447]
at least one software execution characteristic, liable to be
monitored at least in part in a unit 6, [0448] at least one
criterion to abide by for at least one software execution
characteristic, [0449] detection means 17 to implement in a unit 6
and enabling to detect that at least one software execution
characteristic does not abide by at least one associated criterion,
[0450] and coercion means 18 to implement in a unit 6 and enabling
to inform the data processing system 3 and/or modify the execution
of a software when at least one criterion is not abided by, [0451]
and in the case where the protection process according to the
invention implements the principle of protection by detection and
coercion using as characteristic a variable of measurement of the
software execution, are also defined: [0452] as software execution
characteristic liable to be monitored, a variable of measurement of
the usage of a functionality of a software, [0453] as criterion to
abide by, at least one threshold associated to each variable of
measurement, [0454] and actualization means enabling to update at
least one variable of measurement, [0455] and in the case where the
protection process according to the invention also implements a
first preferred variant embodiment of the principle of protection
by detection and coercion using as characteristic a variable of
measurement of the software execution, are also defined: [0456] for
at least one variable of measurement, several associated
thresholds, [0457] and different coercion means corresponding to
each of said thresholds, [0458] and in the case where the
protection process according to the invention implements a second
preferred variant embodiment of the principle of protection by
detection and coercion using as characteristic a variable of
measurement of the software execution, are also defined refilling
means enabling to add at least one additional usage to at least one
software functionality monitored by a variable of measurement,
[0459] and in the case where the protection process according to
the invention implements the principle of protection by detection
and coercion using as characteristic a profile of software usage,
are also defined: [0460] as software execution characteristic
liable to be monitored, a profile of software usage, [0461] and as
criterion to abide by, at least one feature of software execution,
[0462] and in the case where the protection process according to
the invention implements the principle of protection by detection
and coercion using as feature of execution to abide by, the
monitoring of the execution chaining, are also defined: [0463] an
instructions set whose instructions are liable to be executed in
the unit 6, [0464] a set of instructions commands for said
instructions set, said instructions commands being liable to be
executed in the data processing system 3 and to trigger in the unit
6 the execution of the instructions, [0465] as profile of usage,
the chaining of the instructions, [0466] as feature of execution,
an expected chaining for the execution of the instructions, [0467]
as detection means 17, means enabling to detect that the chaining
of the instructions does not correspond to the expected one, [0468]
and as coercion means 18, means enabling to inform the data
processing system 3 and/or to modify the functioning of the portion
of protected software 2p when the chaining of the instructions does
not correspond to the expected one, [0469] and in the case where
the protection process according to the invention implements a
preferred variant embodiment of the principle of protection by
detection and coercion using as feature of execution to abide by,
the monitoring of the execution chaining, are also defined: [0470]
as instructions set, an instructions set whose at least some
instructions work with registers and use at least one operand with
the intention of returning a result, [0471] for at least some of
the instructions working with registers: [0472] a part PF defining
the functionality of the instruction, [0473] and a part defining
the expected chaining for the execution of the instructions and
including bits fields corresponding to: [0474] an identification
field of the instruction CII, [0475] and for each operand of the
instruction: [0476] a flag field CD.sub.k, [0477] and an expected
identification field CIP.sub.k of the operand, [0478] for each
register belonging to the exploitation means and used by the
instructions set, a generated identification field CIG.sub.v in
which is automatically memorized the identification of the last
instruction which has returned its result in said register, [0479]
as detection means 17, means enabling, during the execution of an
instruction, for each operand, when the flag field CD.sub.k imposes
it, to check the equality of the generated identification field
CIG.sub.v, corresponding to the register used by said operand, and
the expected identification field CIP.sub.k of the origin of said
operand, [0480] and as coercion means 18, means enabling to modify
the result of the instructions, if at least one of the checked
equalities is false. [0481] and in the case where the protection
process according to the invention implements the principle of
protection by renaming, are also defined: [0482] as a triggering
command, an instruction command, [0483] as a dependent function, an
instruction, [0484] as an order, at least one argument for a
triggering command, corresponding at least in part to the
information transmitted by the data processing system 3 to the unit
6, so as to trigger the execution of the corresponding dependent
function, [0485] a method of renaming of the orders enabling to
rename the orders so as to obtain triggering commands with renamed
orders, [0486] and restoring means 20 designed to be used in the
unit 6 during the usage phase U, and enabling to restore the
dependent function to execute, from the renamed order, [0487] and
in the case where the protection process according to the invention
implements a variant of the principle of protection by renaming, is
also defined for at least one dependent function, a family of
dependent functions algorithmically equivalent, but triggered by
triggering commands whose renamed orders are different [0488] and
in the case where the protection process according to the invention
implements one of the preferred embodiments of the variant of the
principle of protection by renaming, are also defined for at least
one dependent function, a family of algorithmically equivalent
dependent functions: [0489] by concatenating a field of noise to
the information defining the functional part of the dependent
function to execute in the unit 6, [0490] or by using the
identification field of the instruction CII and the expected
identification fields CIP.sub.k of the operands. [0491] and in the
case where the protection process according to the invention
implements a preferred variant of the principle of protection by
renaming, are also defined: [0492] as method of renaming of the
orders, a ciphering method to cipher the orders, [0493] and as
restoring means 20, means implementing a deciphering method to
decipher the renamed orders and thus restore the identity of the
dependent functions to execute in the unit 6.
[0494] During the prior protection sub-phase P.sub.1, the
definitions stage S.sub.11, is followed by a stage called
"construction stage S.sub.12". During such a stage S.sub.12, are
constructed the transfer means 12, 13 and the exploitation means
corresponding to the definitions of the definitions stage
S.sub.11.
[0495] During this construction stage S.sub.12, are therefore
carried out: [0496] the construction of the transfer means 12, 13
enabling, during the usage phase U, the transfer of data between
the data processing system 3 and the unit 6, [0497] the
construction: [0498] of the exploitation means enabling the unit 6,
during the usage phase U to also implement the detection means 17
and the coercion means 18, [0499] and possibly of the exploitation
means enabling the unit 6, during the usage phase U to also
implement the actualization means, [0500] and possibly of the
exploitation means enabling the unit 6, during the usage phase U to
also implement the refilling means, [0501] and possibly of the
exploitation means also enabling the unit 6, during the usage phase
U to execute the instructions of the instructions set, [0502] and
when the principle of protection by renaming is also implemented,
the construction of the exploitation means enabling the unit 6,
during the usage phase U to also implement the restoring means.
[0503] The construction of the exploitation means is carried out
classically, through a program development unit and taking into
account the definitions intervened in the definitions stages
S.sub.11. Such a unit is described in the rest of the description
in FIG. 110.
[0504] During the prior protection sub-phase P.sub.1, the
construction stage S.sub.12 can be followed by a stage called
"pre-customization stage S.sub.13". During this pre-customization
stage S.sub.13, at least a part of the transfer means 13 and/or the
exploitation means are uploaded to at least one blank unit 60, with
the intention of obtaining at least one pre-customized unit 66. It
should be observed that part of the exploitation means, once
transferred to a pre-customized unit 66, is no longer directly
accessible outside said pre-customized unit 66. The transfer of the
exploitation means to a blank unit 60 can be carried out through an
adapted pre-customization unit, which is described in the rest of
the description in FIG. 120. In the case of a pre-customized unit
66, constituted by a chip card 7 and its reader 8, the
pre-customization concerns only the chip card 7.
[0505] During the prior protection sub-phase P.sub.1, after the
definitions stage S.sub.11 and, possibly after the construction
stage S.sub.12, a stage called "tools making stage S.sub.14" can
take place. During this tools making stage S.sub.14 are made tools
enabling to help generate protected software or automate the
protection of software. Such tools enable: [0506] to help choose or
to choose automatically in the vulnerable software 2v to protect:
[0507] the execution characteristic(s) to monitor and, possibly,
the algorithmic processing(s) liable to be split into instructions
remotable in the unit 6, [0508] the portion(s) liable to be
modified, [0509] and when the principle of protection by variable
is also implemented, the variable(s) liable to be remoted in the
unit 6, [0510] and when the principle of protection by renaming is
also implemented, the algorithmic processing(s) liable to be split
into dependent functions remotable in the unit 6 and for which the
orders of the triggering commands can be renamed, [0511] and when
the principle of protection by conditional branch is also
implemented, the conditional branch(es) whose functionality is
liable to be remoted in the unit 6, [0512] and, possibly, to help
generate protected software or to automate the protection of
software.
[0513] These different tools can be carried out independently or in
combination and each tool can have various forms, such as for
instance pre-processor, assembler, compiler, etc.
[0514] The prior protection sub-phase P.sub.1 is followed by a
subsequent protection sub-phase P.sub.2 which depends on the
vulnerable software 2v to protect. This subsequent protection
sub-phase P.sub.2 is composed of several stages as well. The first
stage corresponding to the implementation of the principle of
protection by detection and coercion is called "creation stage
S.sub.21". During this creation stage S.sub.21, the choices made
during the definition stage S.sub.11 are used. With the aid of said
choices and possibly of tools constructed during the tools making
stage S.sub.14, the protected software 2p is created: [0515] a by
choosing at least one software execution characteristic to monitor,
among the software execution characteristics liable to be
monitored, [0516] a by choosing at least one criterion to abide by
for at least one chosen software execution characteristic, [0517]
by choosing, at least one algorithmic processing which, during the
execution of the vulnerable software 2v, uses at least one operand
and enables to obtain at least one result, and for which at least
one chosen software execution characteristic, is to be monitored,
[0518] by choosing at least one portion of the source of the
vulnerable software 2vs containing, at least one chosen algorithmic
processing, [0519] by producing the source of the protected
software 2ps from the source of the vulnerable software 2vs, by
modifying at least one chosen portion of the source of the
vulnerable software 2vs to obtain at least one modified portion of
the source of the protected software 2ps, this modification being
such that: [0520] during the execution of the protected software 2p
a first execution part 2pes is executed in the data processing
system 3 and a second execution part 2peu is executed in a unit 6,
obtained from the blank unit 60 after upload of information, [0521]
the second execution part 2peu executes at least the functionality
of at least one chosen algorithmic processing, [0522] and during
the execution of the protected software 2p, at least one chosen
execution characteristic is monitored by means of the second
execution part 2peu and the fact that a criterion is not abided by
leads to a modification of the execution of the protected software
2p, [0523] and by producing: [0524] a first object part 2pos of the
protected software 2p, from the source of the protected software
2ps, said first object part 2pos being such that during the
execution of the protected software 2p, appears a first execution
part 2pes which is executed in the data processing system 3 and
whose at least a portion takes into account that at least one
chosen software execution characteristic is monitored, [0525] and a
second object part 2pou of the protected software 2p, containing
the exploitation means implementing the detection means 17 and the
coercion means 18, said second object part 2pou being such that,
after upload to the blank unit 60 and during the execution of the
protected software 2p, appears the second execution part 2peu by
means of which at least one chosen software execution
characteristic is monitored and by means of which the fact that a
criterion is not abided by leads to a modification of the execution
of the protected software 2p.
[0526] Naturally, the principle of protection by detection and
coercion according to the invention can be applied directly during
the development of a new software without requiring the prior
realization of a vulnerable software 2v. In this way, a protected
software 2p is obtained directly.
[0527] For the implementation of the principle of protection by
detection and coercion using as characteristic a variable of
measurement of the software execution, the protected software 2p is
modified: [0528] by choosing as software execution characteristic
to monitor, at least one variable of measurement of the usage of at
least one functionality of a software, [0529] by choosing: [0530]
at least one functionality of the protected software 2p whose usage
is liable to be monitored using a variable of measurement, [0531]
at least one variable of measurement used to quantify the usage of
said functionality, [0532] at least one threshold associated to a
chosen variable of measurement corresponding to a limit of usage of
said functionality, [0533] and at least one method of update of a
chosen variable of measurement depending on the usage of said
functionality, [0534] and by modifying at least one chosen portion
of the source of the protected software 2ps, this modification
being such that, during the execution of the protected software 2p,
the variable of measurement is actualized by means of the second
execution part 2peu depending on the usage of said functionality,
and at least one threshold crossing is taken into account.
[0535] For the implementation of a first preferred variant
embodiment of the principle of protection by detection and coercion
using, as characteristic, a variable of measurement, the protected
software 2p is modified: [0536] by choosing in the source of the
protected software 2ps, at least one chosen variable of measurement
to which must be associated several thresholds corresponding to
different limits of usage of the functionality, [0537] by choosing
at least two thresholds associated to the chosen variable of
measurement, [0538] and by modifying at least one chosen portion of
the source of the protected software 2ps, this modification being
such that, during the execution of the protected software 2p, the
crossings of the various thresholds are taken into account
differently, by means of the second execution part 2peu.
[0539] For the implementation of a second preferred variant
embodiment of the principle of protection by detection and coercion
using as characteristic, a variable of measurement, the protected
software 2p is modified: [0540] by choosing in the source of the
protected software 2ps, at least one chosen variable of measurement
enabling to limit the usage of a functionality and which must be
able to be credited with at least one additional usage, [0541] and
by modifying at least one chosen portion, this modification being
such that during a phase called of refilling, at least one
additional usage of at least one functionality corresponding to a
chosen variable of measurement can be credited.
[0542] For the implementation of the principle of protection by
detection and coercion using as characteristic, a profile of
software usage, the protected software 2p is modified: [0543] by
choosing as software execution characteristic to monitor at least
one profile of software usage, [0544] by choosing at least one
feature of execution by which at least one chosen profile of usage
must abide, [0545] and by modifying at least one chosen portion of
the source of the protected software 2ps, this modification being
such that, during the execution of the protected software 2p, the
second execution part 2peu abides by all the chosen features of
execution.
[0546] For the implementation of the principle of protection by
detection and coercion using as feature of execution to abide by,
the monitoring of the execution chaining, the protected software 2p
is modified: [0547] by modifying at least one chosen portion of the
source of the protected software 2ps, this modification being such
that: [0548] at least one chosen algorithmic processing is split so
that during the execution of the protected software 2p, said
algorithmic processing is executed by means of the second execution
part 2peu, using instructions, [0549] for at least one chosen
algorithmic processing, instructions commands are 3 integrated to
the source of the protected software 2ps, so that during the
execution of the protected software 2p, each instruction command is
executed by the first execution part 2pes and triggers in the unit
6, the execution by means of the second execution part 2peu, of an
instruction, [0550] a sequence of the instructions commands is
chosen among the set of sequences allowing the execution of the
protected software 2p, [0551] and the chaining by which must abide
at least some of the instructions during their execution in the
unit 6 is specified.
[0552] During the subsequent protection sub-phase P.sub.2, and when
at least another principle of protection is applied in addition to
the principle of protection by detection and coercion, a
"modification stage S.sub.22" takes place. During this modification
stage S.sub.22, are used the definitions intervened in the
definitions stage S.sub.11. Using said definitions and possibly
tools constructed during the tools making stage S.sub.14, the
protected software 2p is modified to allow the implementation of
the principles of protection according to one of the arrangements
herebefore defined.
[0553] When the principle of protection by variable is implemented,
the protected software 2p is modified: [0554] by choosing at least
one variable used in at least one chosen algorithmic processing,
which during the execution of the protected software 2p, partially
defines the state of the protected software 2p, [0555] by modifying
at least one chosen portion of the source of the protected software
2ps, this modification being such that during the execution of the
protected software 2p, at least one chosen variable or at least one
copy of chosen variable resides in the unit 6, [0556] and by
producing: [0557] the first object part 2pos of the protected
software 2p, said first object part 2pos being such that during the
execution of the protected software 2p, at least one portion of the
first execution part 2pes takes also into account that at least one
variable or at least one copy of variable resides in the unit 6,
[0558] and the second object part 2pou of the protected software
2p, said second object part 2pou being such that, after upload to
the unit 6 and during the execution of the protected software 2p,
appears the second execution part 2peu by means of which at least
one chosen variable, or at least one copy of chosen variable
resides too in the unit 6.
[0559] When the principle of protection by renaming is implemented,
the protected software 2p is modified: [0560] by choosing in the
source of the protected software 2ps, triggering commands, [0561]
by modifying at least one chosen portion of the source of the
protected software 2ps by renaming the orders of the chosen
triggering commands, so as to conceal the identity of the
corresponding dependent functions, [0562] and by producing: [0563]
the first object part 2pos of the protected software 2p, said first
object part 2pos being such that during the execution of the
protected software 2p, the triggering commands with renamed orders
are executed, [0564] and the second object part 2pou of the
protected software 2p containing the exploitation means also
implementing the restoring means 20, said second object part 2pou
being such that, after upload to the unit 6 and during the
execution of the protected software 2p, the identity of the
dependent functions whose execution is triggered by the first
execution part 2pes is restored by means of the second execution
part 2peu, and the dependent functions are executed by means of the
second execution part 2peu.
[0565] For the implementation of a variant of the principle of
protection by renaming, the protected software 2p is modified:
[0566] by choosing, in the source of the protected software 2ps at
least one triggering command with renamed order, [0567] and by
modifying at least one chosen portion of the source of the
protected software 2ps by replacing at least the renamed order of
one chosen triggering command with renamed order, with another
renamed order, triggering a dependent function of the same
family.
[0568] When the principle of protection by conditional branch is
implemented, the protected software 2p is modified: [0569] by
choosing, in the source of the protected software 2ps, at least one
conditional branch carried out in at least one chosen algorithmic
processing, [0570] by modifying at least one chosen portion of the
source of the protected software 2ps, this modification being such
that during the execution of the protected software 2p, the
functionality of at least one chosen conditional branch is
executed, by means of the second execution part 2peu, in the unit
6, [0571] and by producing: [0572] the first object part 2pos of
the protected software 2p, said first object part 2pos being such
that during the execution of the protected software 2p, the
functionality of at least one chosen conditional branch is executed
in the unit 6, [0573] and the second object part 2pou of the
protected software 2p, said second object part 2pou being such
that, after upload to the unit 6 and during the execution of the
protected software 2p, appears the second execution part 2peu by
means of which the functionality of at least one chosen conditional
branch is executed,
[0574] For the implementation of a preferred embodiment of the
principle of protection by conditional branch, the protected
software 2p is modified: [0575] by choosing, in the source of the
protected software 2ps, at least one series of chosen conditional
branches, [0576] by modifying at least one chosen portion of the
source of the protected software 2ps, this modification being such
that during the execution of the protected software 2p, the overall
functionality of at least one chosen series of conditional branches
is executed, by means of the second execution part 2peu, in the
unit 6, [0577] and by producing. [0578] the first object part 2pos
of the protected software 2p, said first object part 2pos being
such that during the execution of the protected software 2p, the
functionality of at least one chosen series of conditional branches
is executed in the unit 6, [0579] and the second object part 2pou
of the protected software 2p, said second object part 2pou being
such that, after upload to the unit 6 and during the execution of
the protected software 2p, appears the second execution part 2peu
by means of which the overall functionality of at least one chosen
series of conditional branches is executed,
[0580] Naturally, the principles of protection according to the
invention can be applied directly during the development of a new
software without requiring the prior carrying out of intermediate
protected pieces of software. In this way, the creation stage
S.sub.21, and the modification stage S.sub.22 can be carried out
concomitantly so as to obtain directly the protected software
2p.
[0581] During the subsequent protection sub-phase P.sub.2, after
the creation stage S.sub.21 of the protected software 2p, and
possibly after the modification stage S.sub.22, a stage called
"customization stage S.sub.23" takes place. During this
customization stage S.sub.23, the second object part 2pou
containing the exploitation means is uploaded to at least one blank
unit 60, with the intention of obtaining at least one unit 6, or a
part of the second object part 2pou possibly containing the
exploitation means is uploaded to at least one pre-customized unit
66, with the intention of obtaining at least one unit 6. The
uploading of this customization information enables to make
operational at least one unit 6. It should be observed that part of
said information, once transferred to a unit 6, is not directly
accessible outside said unit 6. The transfer of the customization
information to a blank unit 60 or a pre-customized unit 66 can be
carried out through an adapted customization unit which is
described in the rest of the description in FIG. 150. In the case
of a unit 6, constituted by a chip card 7 and its reader 8, the
customization concerns only the chip card 7.
[0582] For the implementation of the protection phase P, various
technical means are described more precisely in relation to FIGS.
110, 120, 130, 140 and 150.
[0583] FIG. 110 illustrates an embodiment of a system 25 enabling
to implement the construction stage S.sub.12 which takes into
account the definitions intervened during the definitions stage
S.sub.11, and during which are constructed the transfer means 12,
13 and possibly, the exploitation means intended for the unit 6.
Such a system 25 includes a program development unit or workstation
which has classically the form of a computer comprising a system
unit, a screen, peripherals such as keyboard-mouse, and including,
among others, the following programs: file editors, assemblers,
pre-processors, compilers, interpretors, debuggers and link
editors.
[0584] FIG. 120 illustrates an embodiment of a pre-customization
unit 30 enabling to upload at least in part the transfer means 13
and/or the exploitations means to at least one blank unit 60 with
the intention of obtaining a pre-customized unit 66. Said
pre-customization unit 30 includes reading and writing means 31
enabling to electrically pre-customize, a blank unit 60 so as to
obtain a pre-customized unit 66 to which the transfer means 13
and/or the exploitations means have been uploaded. The
pre-customization unit 30 can also include physical customization
means 32 of the blank unit 60 which can for instance, have the form
of a printer. In the case where the unit 6 is constituted by a chip
card 7 and its reader 8, the pre-customization generally concerns
only the chip card 7.
[0585] FIG. 130 illustrates an embodiment of a system 35 enabling
to carry out the making of the tools enabling to help generate
protected software or to automate software protection. Such a
system 35 includes a program development unit or workstation which
has classically the form of a computer comprising a system unit, a
screen, peripherals such as keyboard-mouse, and including, among
others, the following programs: file editors, assemblers,
pre-processors, compilers, interpreters, debuggers and link
editors.
[0586] FIG. 140 illustrates an embodiment of a system 40 enabling
to create directly a protected software 2p or to modify a
vulnerable software 2v with the intention of obtaining a protected
software 2p. Such a system 40 includes a program development unit
or workstation which has classically the form of a computer
comprising a system unit, a screen, peripherals such as
keyboard-mouse, and including, among others, the following
programs: file editors, assemblers, pre-processors, compilers,
interpretors, debuggers and link editors, as well as tools enabling
to help generate protected software or to automate software
protection.
[0587] FIG. 150 illustrates an embodiment of a customization unit
45 enabling to upload the second object part 2pou to at least one
blank unit 60 with the intention of obtaining at least one unit 6
or to upload a part of the second object part 2pou to at least one
pre-customized unit 66 with the intention of obtaining at least one
unit 6. Said customization unit 45 includes reading and writing
means 46 enabling to electrically customize, at least one blank
unit 60 or at least one pre-customized unit 66, so as to obtain at
least one unit 6. At the close of this customization, a unit 6
includes the information necessary to the execution of the
protected software 2p. The customization unit 45 can also include
physical customization means 47 for at least one unit 6 which can
for instance, have the form of a printer, In the case where a unit
6 is constituted by a chip card 7 and its reader 8, the
customization generally concerns only the chip card 7.
[0588] The protection process according to the invention can be
implemented with the following improvements: [0589] It can be
planned to use jointly several processing and memorizing units
between which is divided out the second object part 2pou of the
protected software 2p so that their joint use enables to execute
the protected software 2p, the absence of at least one of said
processing and memorizing units preventing the usage of the
protected software 2p. [0590] In the same way, after the
pre-customization stage S.sub.3 and during customization stage
S.sub.23, the part of the second object part 2pou necessary to
transform the pre-customized unit 66 into a unit 6 can be contained
in a processing and memorizing unit used by the customization unit
45 so as to limit the access to said part of the second object part
2pou. Naturally, said part of the second object part 2pou can be
divided out between several processing and memorizing units so that
said part of the second object part 2pou is accessible only during
the joint use of said processing and memorizing units.
* * * * *