Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Thomas Hiscock

Olivier Savry

Mustapha El Majihi

Florian Pebay-Peyroula

Damien Courousse

Amine Jaamoum

Billal Ighilahriz

A management system for managing a cache memory including a randomization module configured for generating a random value for each process of accessing the cache memory, and for transforming addresses of the cache memory with said random value into randomized addresses, a history table configured to store therein on each line an identification pair associating a random value corresponding to an access process, with an identifier of the corresponding access process, so forming identification pairs that are operative to dynamically partition the cache memory while registering the access to the cache memory, and a state machine configured to manage each process of accessing the cache memory according to the identification pairs stored in the history table.

Method and system for managing a cache memory

A method for the execution of a binary code defining a data structure including a particular field to be read using a pointer, this method including writing, to the main memory, the value of the particular field associated with a first identifier of a pointer that points directly to this particular field, this identifier being determined from an identifier of the particular field that differs for all of the fields of the data structure that are adjacent to the particular field, and then constructing a pointer that points directly to this particular field, this construction including determining an identifier of this constructed pointer, and then checking that the identifier constructed in step b) corresponds to the identifier associated with this particular field in step a), and when these pointer identifiers do not match, triggering the signaling of an execution fault.

Method for the execution of a binary code of a computer program by a microprocessor

A method for executing a computer program includes incorporating, into metadata of a block containing a line of code to be accessed using a pointer, a first pointer identifier associated with the line of code to be accessed, then obtaining a pointer including a first range of bits containing the address of the line of code to be accessed, and a different second range of bits containing a second pointer identifier, then verifying that the second pointer identifier contained in the obtained pointer corresponds to the first pointer identifier associated with the line of code to be accessed and contained in the metadata of the loaded block, and when the first and second pointer identifiers do not correspond, then the security module triggers signaling of an execution fault.

Method for executing a computer program by means of an electronic apparatus

This device comprises a fast sampler comprising:

Device and method for generating a random number drawn according to a nonuniform distribution

A method for executing a computer program, wherein when a microprocessor writes a block of Nbytes of a datum of a block of cleartext data stored in an unencrypted memory, a security module switches a validity indicator associated with this block of Nbytes to an active state wherein it indicates that this block of bytes is valid, and each time a block of Nbytes of a datum of the block of cleartext data is loaded by the microprocessor from the unencrypted memory, the hardware security module verifies whether the validity indicator associated with this block of Nbytes is in its active state and, if such is the case, processing, by the microprocessor, of this block of Nbytes is permitted, and, if such is not the case, processing, by the microprocessor, of this block of Nbytes is forbidden.

A method for executing a polymorphic machine code, wherein: for each branching address at which a base block of a flow of generated instructions starts, the microprocessor automatically adds, in the generated flow of instructions, a renewal instruction suitable, when it is executed, for triggering the renewal of an initialization vector of a module for decryption by flow with a specific value associated with this branching address, then a flow encryption module encrypts the flow of instructions as it is generated and, during this encryption, each base block is encrypted using a specific value associated with the branching address at which it starts. Only the instruction flow encrypted in this way is recorded in the main memory. During execution of the encrypted instruction flow, the added renewal instructions are executed as they are encountered.

Method for executing a polymorphic machine code of a predetermined function by a microprocessor

Method for managing a cache memory comprising:

Method for managing a cache memory of an electronic computer

A method for managing a cache memory, including executing first and second processes, when the second process modifies the state of the cache memory, updating the value of an indicator associated with this second process, and comparing the value of this indicator to a predefined threshold and, when this predefined threshold is exceeded, detecting an abnormal use of the cache memory by the second process, in response to this detection, modifying pre-recorded relationships in order to associate with the identifier of the second process a value of a parameter q different from the value of the parameter q associated with the first process so that, after this modification, when the received address of a word to be read is the same for the first and second processes, then the set addresses used to read this word from the cache memory are different.

Method for managing a cache memory of an electronic processor

A modular reduction device particularly for cryptography on elliptical curves. The device includes a Barrett modular reduction circuit and a cache memory in which the results of some precalculations are carried out. When the result is not present in the cache memory, a binary division circuit makes the precalculation and stores the result in the cache memory.

Modular reduction device

A method of executing a program operating on data encrypted by a homomorphic encryption. Execution of a program instruction includes the homomorphic evaluation of an associated function in the ciphertext space, homomorphic masking of the result of the evaluation with a previously encrypted random sequence, decryption of the evaluation result thus masked followed by a new encryption and then homomorphic unmasking in the ciphertext space. The result of execution of the instruction does not appear in plain text at any time during execution of the instruction.

Method for confidential execution of a program operating on data encrypted by a homomorphic encryption

A method of encrypting a program instructions stream and a method of executing an instructions stream thus encrypted. Instructions are translated into binary code before being encrypted by a stream cipher method. When the program contains a conditional or unconditional branch instruction, an instruction is inserted in the program to initialize the pseudo-random sequence generator using an initialization vector, the initialization vector being used to generate the pseudo-random sequence for encryption and decryption of instructions at the branch address. Instructions can be decrypted and executed on-the-fly without needing to know their physical addresses, even in the presence of a branch.

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Grenoble, France

Thomas Hiscock