Cloakware Corporation

Irdeto B.v.

Irdeto Canada Corporation

Nortel Networks Corporation

Northern Telecom Limited

Harold J Johnson

Stanley T Chow

Yuan Xiang Gu

Yuan X Gu

Yongxin Zhou

Alexander James Main

Michael James Wiener

Philip A Eisen

Robert Durand

Mark Andrew Turnbull

Yuan Gu

Alec Main

Yaser Eftekhari

Alexander Shokurov

Bahman Sistany

Becky Laiping Chang

There is described a method of protecting an item of software so as to obfuscate a condition which causes a variation in control flow through a portion of the item of software dependent on whether the condition is satisfied, wherein satisfaction of the condition is based on evaluation of one or more condition variables. The method comprises: (i) modifying the item of software such that the control flow through said portion is not dependent on whether the condition is satisfied; and (ii) inserting a plurality of identity transformations into expressions in said portion of the modified item of software, wherein the identity transformations are defined and inserted such that, in the absence of tampering, they maintain the results of the expressions if the condition is satisfied and such that they alter the results of the expressions if the condition is not satisfied, wherein each identity transformation is directly or indirectly dependent on at least one of the one or more condition variables. New variables may be defined as part of this method. There are also described associated apparatuses, computer programs and the like.

Protecting an item of software

A method comprising, during runtime of an item of software that comprises one or more portions of code and verification code: the verification code generating verification data using (a) runtime data generated by the one or more portions of code and (b) one or more predetermined parameters, the verification data representing an element of a predetermined first set of data elements; and providing the verification data to an integrity checker arranged to (i) identify that a modification relating to the verification code has not occurred if the verification data represents an element of a predetermined second set of data elements, wherein the second set is a subset of the first set, and (ii) identify that a modification relating to the verification code has occurred if the verification data does not represent an element of the second set; wherein it is computationally infeasible to determine an element of the second set without knowledge of the one or more predetermined parameters or data related to the one or more predetermined parameters; and wherein, in the absence of a modification relating to the verification code, use of the one or more predetermined parameters by the verification code ensures that the verification data represents an element of the second set and use of the runtime data by the verification code controls which element of the second set is represented by the generated verification data.

Software integrity verification

A method comprising: carrying out optimization of an item of software in a first intermediate representation; carrying out protection of the item of software in a second intermediate representation different to the first intermediate representation.

Optimizing and protecting software

Systems and techniques for securing accessible computer-executable program code and systems are provided. One or more base functions may be generated and blended with existing program code, such that it may be difficult or impossible for a potential attacker to distinguish the base functions from the existing code. The systems and code also may be protected using a variety of other blending and protection techniques, such as fractures, variable dependent coding, dynamic data mangling, and cross-linking, which may be used individually or in combination, and/or may be blended with the base functions.

Securing accessible systems using base function encoding

Methods and devices for thwarting code and control flow based attacks on software. The source code of a subject piece of software is automatically divided into basic blocks of logic. Selected basic blocks are amended so that their outputs are extended. Similarly, other basic blocks are amended such that their inputs are correspondingly extended. The amendments increase or create dependencies between basic blocks such that tampering with one basic block's code causes other basic blocks to malfunction when executed.

System and method of interlocking to protect software-mediated program and device behaviours

Securing accessible systems using variable dependent coding

Securing accessible systems using dynamic data mangling

Attacks by computer viruses, worm programs, and other hostile software ('malware'), have become very serious problems for computer systems connected to large communication networks such as the Internet. One potential defense against such attacks is to employ diversity&#x2014;that is, making each copy of the attacked software different. However, existing diversity techniques do not offer sufficient levels of protection. The invention provides an effective diversity solution by applying tamper resistant software (TRS) encoding techniques, to the communications that take place between software components, with corresponding changes to the code handling those communications. These communications may include, for example, data passed between software routines via parameters or mutually accessible variables, light-weight messages, signals and semaphores passed between threads, and messages passed between software processes. Effective TRS encoding techniques include data-flow encoding and mass-data encoding techniques.

Secure method and system for computer protection

A method for rendering software resistant to reverse engineering. Replace at least one first constant (mathematical expression, etc.) in a computational expression with a second mixed mathematical and bitwise-Boolean expression, the first constant being simpler than the second expression and the second expression being based on the value or the variables found in the first constant (or expression). Evaluation of the second mixed mathematical and bitwise-Boolean expression produces a value preserving the value of the first constant, either: with the original value of the first constant or the original value of the result of the first expression, in which case the second mixed mathematical and bitwise-Boolean expression is obtained from the first constant by converting the first constant by mathematical identities; or, in an encoded form, as a new value, which can be converted back to the original value of the first constant by applying an information-preserving decoding function, in which case the second mixed mathematical and bitwise-Boolean expression is obtained from the first constant by modifying the first constant by a combination of conversion according to mathematical identities and transformation according to an information preserving encoding function.

System and method of interlocking to protect software&#x2014;mediated program and device behaviors

Attacks by computer viruses, worm programs, and other hostile software ('malware'), have become very serious problems for computer systems connected to large communication networks such as the Internet. One potential defence against such attacks is to employ diversity&#x2014;that is, making each copy of the attacked software different. However, existing diversity techniques do not offer sufficient levels of protection. The invention provides an effective diversity solution by applying tamper resistant software (TRS) encoding techniques, to the communications that take place between software components, with corresponding changes to the code handling those communications. These communications may include, for example, data passed between software routines via parameters or mutually accessible variables, light-weight messages, signals and semaphores passed between threads, and messages passed between software processes. Effective TRS encoding techniques include data-flow encoding and mass-data encoding techniques.

Systems and methods which may be implemented as software to control access to content streams transmitted from a service provider's server. A software solution forces each set top box (STB) to periodically uplink to the server and to receive authentication from that server. To prevent spoofing, the server periodically loads to each STB at least one unique key that is required to access the content stream or that is required for authentication. The key or keys may be periodically revoked and/or replaced by the server. The frequency of the revocation and/or replacement of the key is ideally not fixed. Also, the server may periodically upgrade the decoding and/or authentication software on the STBs via the uplink.

Software conditional access system

Methods and systems related to increasing the cryptographic security of keys used by software with cryptographic functions. This is done by increasing the mathematical complexity of the software. The components and functions used by the software are first determined and, using these components, functions, and the data exchanged between them, the software is made more resistant to analysis. The methods used in increasing analytical resistance are grouped into 3 general types: adjusting the information exchanged between the components, replacing some components with different but related components, and adjusting the data flow between the components.

System and method for protecting computer software from a white box attack

There is a need in the computer software and data industries to protect content from unauthorized access to private information. Alphanumeric passwords have been shown to offer very weak protection. Biometrics (personal traits such as fingerprints and hand-written signatures) offer superior protection, but still have a number of weaknesses. The most significant weakness is that there is no existing way to protect the stored biometric data itself; and once a person's fingerprint data has been obtained by an attacker, the use of that fingerprint can no longer be considered secure. The invention solves the problem by securing the access software application that manages the biometric data using tamper-resistant encoding techniques. These tamper-resistant encoding techniques include: data-flow, control-flow, mass-data and white-box encoding.

Secure method and system for biometric verification

The present invention relates generally to computer software, and more specifically, to a system and method of foiling buffer-overflow and alien-code attacks. The invention protects computers from such attacks by encoding data placed in storage, and varying the encodings used in different storage areas. When the data is needed by a software application, the data is simply decoded in a complementary manner. This prevents storage areas written according to one usage from being used effectively for some other purpose. The method of the invention can be done in a number of ways. For example, a 'protector' engine can be placed between a software application and memory, or the function calls in the software application itself, could be amended to include encoding and decoding. Other embodiments and alternatives are also described.

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Nepean, Canada

Harold J Johnson