# Benoit Chevallier-Mames, Paris FR

## Benoit Chevallier-Mames, Paris FR

Patent application number | Description | Published |
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20100281256 | HASH FUNCTION USING A PILING-UP PROCESS - In the computer data security field, a cryptographic hash function process embodied in a computer system and which is typically keyless, but is highly secure. The process is based on the type of randomness exhibited by well known tetromino stacking games. Computation of the hash value (digest) is the result of executing such a “piling on” (tetromino stacking game) algorithm using the message as an input (a seed) to a pseudo random number generator which generates the game pieces (shapes) from the resulting random numbers, then executing the game algorithm. | 11-04-2010 |

20100281260 | HASH FUNCTION BASED ON POLYMORPHIC CODE - In the field of computer data security, a hash process which is typically keyless and embodied in a computing apparatus is highly secure in terms of being resistant to attack. The hash process uses computer code (software) polymorphism, wherein computation of the hash value for a given message is partly dependent on the content (data) of the message. Hence the computer code changes dynamically while computing each hash value. | 11-04-2010 |

20100304805 | HASH FUNCTION USING A CUE SPORTS GAME PROCESS - In the computer data security field, a cryptographic hash function process embodied in a computer system and which is typically keyless, but is highly secure. The process is based on the type of randomness exhibited by well known table “cue sports” games such as billiards, snooker, and pool played on a billiards table involving the players striking one of a plurality of balls with a cue, the struck ball then hitting other balls, the raised sides of the table, and in some cases one or more balls going into pockets in the corners and/or sides of the table. Computation of the hash value (digest) is the result of providing a model (such as expressed in computer code) of such a game algorithm and using the message as an input to the game algorithm, then executing the game algorithm. A state of the game after a “shot” gives the hash digest value. | 12-02-2010 |

20100304807 | HASH FUNCTION USING A CUE SPORTS GAME PROCESS - In the computer data security field, cryptographic hash function processes embodied in a computer system and which are typically keyless, but are highly secure. The processes are based on the type of randomness exhibited by well known table “cue sports” games such as billiards, snooker, and pool played on a billiards table involving the players striking one of a plurality of balls with a cue, the struck ball then hitting other balls, the raised sides of the table, and in some cases one or more balls going into pockets in the corners and/or sides of the table. Computation of the hash value (digest) is the result of providing a model (such as expressed in computer code) of such a game algorithm and using the message as an input to the game algorithm, then executing the game algorithm. A state of the game after one or several “shots” gives the hash digest value of the message. | 12-02-2010 |

20100304826 | HASH FUNCTION USING A ROULETTE GAME PROCESS - In the computer data security field, a cryptographic hash function process embodied in a computer system and which is typically keyless, but is highly secure. The process is based on the type of randomness exhibited by the well known gambling game of roulette played on a roulette wheel involving dropping a ball onto a partitioned spinning wheel. The ball loses momentum and drops into one of the partitions (pockets) of the wheel. Computation of the hash value (digest) is the result of executing in a model (such as computer code or logic circuitry) such a game algorithm using the message as an input to the game algorithm, then executing the game algorithm. A state of the game (the final ball location) after a ball (or several balls) are played gives the hash digest value of the message. | 12-02-2010 |

20100306541 | HASH FUNCTION USING A CARD SHUFFLING PROCESS - In the computer data security field, a cryptographic hash function process embodied in a computer system and which is typically keyless, but is highly secure. The process is based on the type of chaos introduction exhibited by a game process such as the well known shuffling of a deck of playing cards. Computation of the hash value (digest) is the result of executing in a model (such as computer code or logic circuitry) a game algorithm that models the actual game such as a playing card shuffling algorithm using the message as an input to the algorithm, then executing the card shuffling algorithm on the input. A state (order) of the modeled deck of cards after a shuffle (or multiple shuffles) gives the hash digest value. | 12-02-2010 |

20110040977 | SPONGE AND HASH FUNCTIONS USING A RUBIK'S CUBE PUZZLE PROCESS - The present method is directed, in the computer data security field, to cryptographic sponge and hash function processes which are embodied in a computer system and are typically keyless, but highly secure. The processes are based on the type of randomness exhibited by manipulation of the well known three dimensional Rubik's cube puzzle. Computation of the hash or sponge value (digest) is the result of executing in a model (such as computer code or logic circuitry) an algorithm modeling such a puzzle using the message as an input to the cube puzzle algorithm, then executing the cube puzzle algorithm. A state of the modeled cube puzzle (the final cube puzzle arrangement) after execution gives the sponge or hash digest value of the message. | 02-17-2011 |

20110055576 | HASH FUNCTION USING A HEAP MODELING PROCESS - This discloses, in the computer data security field, a cryptographic hash function process embodied in a computer system and which may be keyless, but is highly secure. The process is based on the type of randomness exhibited by a heap or stack of physical objects such as a heap of pieces of fruit and involves modeling the behavior of such a heap when pieces are removed from the heap. Computation of the hash value (digest) is thereby the result of executing a heap model algorithm using the message as an input to initialize the heap, then executing the heap model algorithm which logically models the process of serially removing objects (pieces of fruit) from the heap at various locations in the modeled heap. | 03-03-2011 |

20110055581 | HASH FUNCTION BASED ON PAINTING TECHNIQUES - In the computer data security field, this disclosure is of cryptographic hash function processes embodied in a computer system and which may be keyless, but are highly secure. The processes are based on the type of randomness exhibited by painting or drawing a picture. Computation of the hash value (digest) is the result of executing in computer code or logic circuitry an algorithm which models such a picture painting process using the message as an input to the picture painting algorithm, then executing the algorithm. A state of the resulting picture gives the hash digest value of the message. Message expansion or a derivation function (e.g., a pseudo random number generation process) may be applied to the message prior to execution of the picture painting process, for enhanced security. | 03-03-2011 |

20110055582 | HASH FUNCTION USING A DOMINO GAME PROCESS - In the computer data security field, cryptographic hash function processes are embodied in a computer system and may be keyless, but are highly secure. The processes are based on the type of randomness exhibited by the well known game of dominos using a set of tiles arranged by players on a surface. Computation of the hash value (digest) is the result of executing in computer code or logic circuitry an algorithm which models such a domino game using the message as an input to the domino game algorithm, then executing the domino game algorithm. A state of the game algorithm which models the final layout of the pieces (tiles) gives the hash digest value of the message. | 03-03-2011 |

20110116624 | SYSTEM AND METHOD FOR DATA OBFUSCATION BASED ON DISCRETE LOGARITHM PROPERTIES - Disclosed herein are systems, computer-implemented methods, and computer-readable storage media for obfuscating data based on a discrete logarithm. A system practicing the method identifies a clear value in source code, replaces the clear value in the source code with a transformed value based on the clear value and a discrete logarithm, and updates portions of the source code that refer to the clear value such that interactions with the transformed value provide a same result as interactions with the clear value. This discrete logarithm approach can be implemented in three variations. The first variation obfuscates some or all of the clear values in loops. The second variation obfuscates data in a process. The third variation obfuscates data pointers, including tables and arrays. The third variation also preserves the ability to use pointer arithmetic. | 05-19-2011 |

20110179281 | HASH FUNCTION USING A QUASI-GROUP OPERATION - In the computer data security field, a cryptographic hash function process is embodied in a computer system or computer software or logic circuitry and is keyless, but highly secure. The process is based on (mathematical) quasi-group operations such as in the known “EDON-R” hash function. But here one or more blank rounds (iterations) of the quasi-group operation are concatenated to the EDON-R hash function operations, to overcome perceived security weaknesses in EDON-R. | 07-21-2011 |

20110246787 | OBFUSCATING TRANSFORMATIONS ON DATA ARRAY CONTENT AND ADDRESSES - In a first computer (digital) data obfuscation process, data which is conventionally arranged in a data structure called an array (e.g., a table) and conventionally stored in computer or computer device memory is obfuscated (masked) by logically or mathematically combining the data, entry-by-entry, with a masking value which is computed as a logical or mathematical function of the entry itself or its index in the array, modulo a security value. The complementary unmasking value is a pointer to the entry's address in the table modulo the security value. In a second computer (digital) data obfuscation process, the addresses (location designations) in memory of a data array are themselves obfuscated (masked) by partitioning the array into blocks of entries and shuffling the order of the data entries in each block by a predetermined algorithm, resulting in a shuffled array also differing from the original array in terms of its size (the total number of entries). | 10-06-2011 |

20110255687 | DATA TRANSFORMATION SYSTEM USING CYCLIC GROUPS - An asymmetric (dual key) data obfuscation process, based on the well known ElGamal cryptosystem algorithm, and which uses multiplicative cyclic groups to transform (obfuscate) digital data for security purposes. In the present system the data need not be a member of the cyclic group, unlike in the ElGamal cryptosystem algorithm. Also, any one of several additional mathematical data transformations are further applied to the transformed data, thereby enhancing security of the transformed data. | 10-20-2011 |

20110302422 | HASH FUNCTION USING A REPEATED FUNCTION WITH SHIFTS - In the data security field, a modular cryptographic hash function process is embodied in a computer system or hardware (circuitry). The process is based on the mode of operation of the known “Shabal” hash function which uses a keyed permutation applied to each word of the message. Here a function is substituted for the permutation and additional final rounds are added to the function. Security is further enhanced over that of the Shabal hash function by avoiding use of the message blocks in computing certain of the data arrays, in order to frustrate known message attacks. | 12-08-2011 |

20120155638 | SECURING KEYS OF A CIPHER USING PROPERTIES OF THE CIPHER PROCESS - In the field of computer enabled cryptography, such as a block cipher, the cipher is hardened against an attack by protecting the cipher key, by applying to it a predetermined linear permutation before using one key to encrypt or decrypt a message. This is especially advantageous in a “White Box” environment where an attacker has full access to the cipher algorithm, including the algorithm's internal state during its execution. This method and the associated computing apparatus are useful where the key is derived through a process and so is unknown when the software code embodying the cipher is compiled. This is typically the case where there are many users of the cipher and each has his own key, or where each user session has its own key. | 06-21-2012 |

20120159186 | SECURING THE IMPLEMENTATION OF A CRYPTOGRAPHIC PROCESS USING KEY EXPANSION - In the field of computer enabled cryptography, such as a keyed block cipher having a plurality of rounds, the cipher is hardened against an attack by protecting the cipher key by means of a key expansion process which obscures the cipher and/or the round keys by increasing their lengths to provide an expanded version of the keys for carrying out encryption or decryption using the cipher. This is especially advantageous in a “White Box” environment where an attacker has full access to the cipher algorithm, including the algorithm's internal state during its execution. This method and the associated computing apparatus are useful where the key is derived through a process and so is unknown when the software code embodying the cipher is compiled. This is typically the case where there are many users of the cipher and each has his own key, or where each user session has its own key. | 06-21-2012 |

20120179919 | SECURING IMPLEMENTATION OF A CRYPTOGRAPHIC PROCESS HAVING FIXED OR DYNAMIC KEYS - In the field of computer enabled cryptography, such as a keyed block cipher having a plurality of rounds, the cipher is hardened against attack by protecting the round keys by (1) combining several cipher operations using a pair of sub-keys (round keys) into one table look-up, or (2) a key masking process which obscures the round keys by providing a masked version of the key operations for carrying out encryption or decryption using the cipher. This approach is especially advantageous in an insecure “White Box” environment where an attacker has full access to execution of the cipher algorithm, including the algorithm's internal state during its execution. | 07-12-2012 |

20120179920 | SECURING CRYPTOGRAPHIC PROCESS KEYS USING INTERNAL STRUCTURES - In the field of cryptography, such as for a computer enabled block cipher, a cipher or other cryptographic process is hardened against an attack by protecting the cipher key or subkeys by using a masking process for these keys. The subkeys are thereby protected by applying to them a mask or set of masks to hide their contents. This is especially advantageous in a “White Box” computing environment where an attacker has full access to the cipher algorithm, including the algorithm's internal state during execution. Further, this method and the associated apparatus are useful where the key is derived through a process and so is unknown when the software code embodying the cipher is compiled. This is typically the case where there are many users of the cipher and each has his own key or where each user session has its own key. | 07-12-2012 |

20120204038 | PERFORMING BOOLEAN LOGIC OPERATIONS USING ARITHMETIC OPERATIONS BY CODE OBFUSCATION - Method and apparatus for obfuscating computer software code, to protect against reverse-engineering of the code. The obfuscation here is of the part of the code that performs a Boolean logic operation such as an exclusive OR on two (or more) data variables. In the obfuscated code, each of the two variables is first modified by applying to it a function which deconstructs the value of each of the variables, and then the exclusive OR operation is replaced by an arithmetic operation such as addition, subtraction, or multiplication, which is performed on the two deconstructed variables. The non-obfuscated result is recovered by applying a third function to the value generated by the arithmetic operation. This obfuscation is typically carried out by suitably annotating (modifying) the original source code. | 08-09-2012 |

20130010963 | MULTIPLICATIVE SPLITS TO PROTECT CIPHER KEYS - In the field of computer enabled cryptography, such as a keyed block cipher having a plurality of rounds, the cipher is hardened against an attack by a protection process which obscures the round keys using the properties of group field automorphisms and applying masks to the states of the cipher, for encryption or decryption. This is especially advantageous in a “White Box” environment where an attacker has full access to the cipher algorithm, including the algorithm's internal state during its execution. This method and the associated computing apparatus are useful for protection against known attacks on “White Box” ciphers, by eliminating S-box operations, together with improved masking techniques and increasing the cipher's complexity against reverse engineering and key storage attacks. | 01-10-2013 |

20130016836 | CRYPTOGRAPHIC PROCESS EXECUTION PROTECTING AN INPUT VALUE AGAINST ATTACKS - A cryptographic process (such as the AES cipher) which uses table look up operations (TLUs) is hardened against reverse engineering attacks intended to recover the table contents and thereby the cipher key. This hardening involves removing any one-to-one correspondence between the TLU inputs and outputs, by altering the output of the TLU dynamically, e.g. at each execution (call) of the TLU. This is done by increasing the size of the tables, applying a dynamically determined mask value to the table input and/or output, or using an inverse of the table. | 01-17-2013 |

20130061061 | PROTECTING LOOK UP TABLES BY MIXING CODE AND OPERATIONS - In the field of computer enabled cryptography, such as a cipher using lookup tables, the cipher is hardened against an attack by a protection process which obscures the lookup tables using the properties of bijective functions and applying masks to the tables' input and output values, for encryption or decryption. This is especially advantageous in a “White Box” environment where an attacker has full access to the cipher algorithm, including the algorithm's internal state during its execution. This method and the associated computing apparatus are useful for protection against known attacks on “White Box” ciphers, by obfuscating lookup table data, thereby increasing the cipher's complexity against reverse engineering and other attacks. | 03-07-2013 |

20130067211 | OPERATIONAL MODE FOR BLOCK CIPHERS - In the field of computer enabled cryptography, such as a keyed block cipher having a plurality of sequenced rounds, the cipher is hardened against attack by a protection process. The protection process uses block lengths that are larger or smaller than and not an integer multiple of those of an associated standard cipher, and without using message padding. This is operative in conjunction with standard block ciphers such as the AES, DES or triple DES ciphers, and also with various block cipher cryptographic modes such as CBC or EBC. | 03-14-2013 |

20130067212 | SECURING IMPLEMENTATION OF CRYPTOGRAPHIC ALGORITHMS USING ADDITIONAL ROUNDS - In the field of computer enabled cryptography, such as a keyed block cipher having a plurality of sequenced rounds, the cipher is hardened against an attack by a protection process which adds rounds to the cipher process. This is especially advantageous in a “White Box” environment where an attacker has full access to the cipher algorithm (process), including the algorithm's internal state during its execution. In one version, a specific number of rounds are added over those of a standard version of the cipher to both encryption and the complementary decryption. The added rounds are inserted immediately after the last of the standard rounds in the sequence. In another version, the added rounds are one or more opposing paired rounds of encryption/decryption or decryption/encryption which effectively cancel each other out, and may be inserted anywhere in the sequence of standard rounds. | 03-14-2013 |

20130138973 | SYSTEM AND METHOD FOR DATA OBFUSCATION BASED ON DISCRETE LOGARITHM PROPERTIES - Disclosed herein are systems, computer-implemented methods, and computer-readable storage media for obfuscating data based on a discrete logarithm. A system practicing the method identifies a clear value in source code, replaces the clear value in the source code with a transformed value based on the clear value and a discrete logarithm, and updates portions of the source code that refer to the clear value such that interactions with the transformed value provide a same result as interactions with the clear value. This discrete logarithm approach can be implemented in three variations. The first variation obfuscates some or all of the clear values in loops. The second variation obfuscates data in a process. The third variation obfuscates data pointers, including tables and arrays. The third variation also preserves the ability to use pointer arithmetic. | 05-30-2013 |

20130232578 | METHOD AND APPARATUS FOR OBFUSCATING PROGRAM SOURCE CODES - First source code of a computer program having a plurality of lines of instructions is received. An obfuscation process is performed on the first source code, including at least two of a shuffling operation, a fertilizing operation, an aggregating operation, and a neutralizing operation. Second source code is generated based on the obfuscation process, where the second source code, when executed by a processor, produces an identical result as the first source code. | 09-05-2013 |

20130259226 | METHODS AND APPARATUS FOR CORRELATION PROTECTED PROCESSING OF CRYPTOGRAPHIC OPERATIONS - A method and an apparatus that generate a plurality of elements randomly as a split representation of an input used to provide an output data cryptographically representing an input data are described. The input may correspond to a result of a combination operation on the elements. Cryptographic operations may be performed on the input data and the elements to generate a plurality of data elements without providing data correlated with the key. The combination operation may be performed on the data elements for the output data. | 10-03-2013 |

20140105402 | DATA PROTECTION USING KEY TRANSLATION - In the data security field, a data protection process embodied in a computer system or computing device or equivalent and which securely descrambles protected (scrambled) data. The process descrambles the data using a dynamic process employing a set of multi-level trees of deterministic functions to generate a descrambling mask value and recover the descrambled message. | 04-17-2014 |

20140165030 | METHODS AND APPARATUS FOR CORRELATION PROTECTED PROCESSING OF DATA OPERATIONS - A method and an apparatus for receiving a first source code having a code block to update the first source code with multiple copies of the code block to protect against correlation attacks are described. The code block can perform one or more operations for execution based on the first source code. The operations can be performed via a random one of the copies of the code block. A second source code based on the updated first source code can be generated to be executed by a processor to produce an identical result as the first source code. | 06-12-2014 |

20140165208 | METHOD AND APPARATUS FOR DYNAMIC OBFUSCATION OF STATIC DATA - A method and an apparatus that provide rewriting code to dynamically mask program data statically embedded in a first code are described. The program data can be used in multiple instructions in the first code. A code location (e.g. an optimal code location) in the first code can be determined for injecting the rewriting code. The code location may be included in two or more execution paths of first code. Each execution path can have at least one of the instructions using the program data. A second code may be generated based on the first code inserted with the rewriting code at the optimal code location. The second code can include instructions using the program data dynamically masked by the rewriting code. When executed by a processor, the first code and the second code can generate identical results. | 06-12-2014 |

20140189366 | Obfuscating Transformations on Data Array Content and Addresses - In a first computer (digital) data obfuscation process, data which is conventionally arranged in a data structure called an array (e.g., a table) and conventionally stored in computer or computer device memory is obfuscated (masked) by logically or mathematically combining the data, entry-by-entry, with a masking value which is computed as a logical or mathematical function of the entry itself or its index in the array, modulo a security value. The complementary unmasking value is a pointer to the entry's address in the table modulo the security value. In a second computer (digital) data obfuscation process, the addresses (location designations) in memory of a data array are themselves obfuscated (masked) by partitioning the array into blocks of entries and shuffling the order of the data entries in each block by a predetermined algorithm, resulting in a shuffled array also differing from the original array in terms of its size (the total number of entries). | 07-03-2014 |

20140301546 | PRECOMPUTING INTERNAL AES STATES IN COUNTER MODE TO PROTECT KEYS USED IN AES COMPUTATIONS - Methods, media, and systems for, in one embodiment, protecting one or more keys in an encryption and/or decryption process can use precomputed values in the process such that at least a portion of the one or more keys is not used or exposed in the process. In one example of a method, internal states of an AES encryption process are saved for use in a counter mode stream cipher operation in which the key used in the AES encryption process is not exposed or used. | 10-09-2014 |

20140348323 | PROTECTING AGAINST WHITE BOX ATTACKS USING COLUMN ROTATION - Various embodiments of a computer-implemented method of information security using block cipher column rotations are described. The cipher state column rotations provide resistance to white box side channel memory correlation attacks designed to reverse-engineer a symmetric cipher key associated with the information security system. The column rotation operations can be performed on the cipher state of a block cipher, and then removed from the result, to provide obfuscation of the data when in memory, while not impacting the resulting output of the cipher or decipher operation. The method additionally includes performing a first rotation of an iteration specific cipher subkey according to the first rotation index, performing an iteration of the block cipher operations on the cipher state matrix, and rotating the columns of the cipher state matrix according to an inverse of the first rotation index. | 11-27-2014 |