Irdeto B.v.

Irdeto Canada Corporation

Cloakare Corporation

Yongxin Zhou

Yuan Xiang Gu

Harold J Johnson

Michael James Wiener

Stanley T Chow

Clifford Liem

Harold Joseph Johnson

Arun Narayanan Kandanchatha

A method for rendering a software program resistant to reverse engineering analysis. At least one first expression in a computational expression or statement of the software program is replaced with a second expression. The first expression being simpler than said second expression and the second expression being based on a value or variables found in said first expression. The second expression produces a value which preserves the value of said first expression. The conversion of the first expression is performed according to a mathematical identity of the form &#x3a3;ae=E, where a, are coefficients, e, are bitwise expressions, whether simple or complex, and E is said first expression.

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

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.

Securing accessible systems using variable dependent coding

A method and system is provided to automatically propagate dependencies from one part of a software application to another previously unrelated part. Propagation of essential code functionality and data to other parts of the program serves to augment common arithmetic functions with Mixed Boolean Arithmetic (MBA) formulae that are bound to pre-existing parts of the program. A software application is first analyzed on a compiler level to determine the program properties which hold in the program. Thereafter, conditions are constructed based on these properties and encoded in formulae that encode the condition in data and operations. Real dependencies throughout the application are therefore created such that if a dependency is broken the program will no longer function correctly.

System and method providing dependency networks throughout applications for attack resistance

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

Systems and methods related to concealing mathematical and logical operations in software. Mathematical and logical operations are disguised by replacing them with logically equivalent expressions. Each equivalent expression has at least two expression constants whose values are based on scaling and bias constants assigned to variables in the original mathematical or logical operation. Each of the expression constants may also be based on additive or multiplicative inverses modulo n of the scaling and bias constants. By replacing the original operations with more complex but logically equivalent expressions containing variables that also involve more operations, the true nature of the original operations is disguised.

System and method for obscuring bit-wise and two's complement integer computations in software

The invention relates to a system and method of hiding cryptographic private keys. While public/private key encryption systems are considered to be secure, the private keys ultimately must be stored in some location&#x2014;in fact, in some digital commerce systems the private key is sent to the end user as part of an executable file such as an audio player and audio file. Thus, attackers can obtain access to the private key. The broad concept of the invention is to split the private key up into parts which are obfuscated, but still kept in a form that allows the encrypted data to be decrypted. One technique for obfuscating the private key uses modulo arithmetic.

Growing community of inventors

Mequon, WI, United States of America

Yongxin Zhou