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

Commissariat a L'energie Atomique

Dover Europe Sarl

Olivier Savry

Thomas Hiscock

Thierry Thomas

Elisabeth Crochon

Damien Bonneton

Pierre-Henri Thevenon

Gaëtan Leplus

Mustapha El Majihi

Florian Pebay-Peyroula

Damien Courousse

Patrick Agnese

Christophe Billard

Jean-Benoit Pierrot

Patrick Soto

Ezinam-Bertrand Talaki

Claude Castelluccia

Sana Ben Hamida

Jean-Benoît Pierrot

A method including generating an initialization vector, then producing a new mask using the generated initialization vector and using a secret key, masking a datum to be written to an internal cache memory using the constructed new mask, to obtain a masked datum, storing, in a given word of the internal cache memory, the masked datum and the generated initialization vector, and unmasking the masked datum, this including extracting the initialization vector contained in the word, reconstructing the mask using the extracted initialization vector and using the secret key, then unmasking the masked datum using the new mask thus reconstructed.

Method for protecting against side-channel attacks

Method for managing a cache memory

A method for executing a machine code using a microprocessor includes, after an operation of decoding a current loaded instruction, constructing a mask from the signals generated by an instruction decoder in response to decoding of the current loaded instruction by the decoder. The constructed mask varies as a function of the current loaded instruction. Subsequently, before an operation of decoding a next loaded instruction, the next loaded instruction is unmasked using the constructed mask.

Generating masks from decoded instructions to apply to fetched instructions for unmasking

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

A method for executing a function, secured by temporal desynchronization, includes when a first legitimate instruction is loaded, noting the opcode of this first legitimate instruction, then constructing a dummy instruction on the basis of this noted opcode, the dummy instruction thus constructed being identical to the first legitimate instruction except that its operands are different, then incorporating the dummy instruction thus constructed into a sequence of dummy instructions used to delay the time at which a second legitimate instruction is executed.

Method for executing a function, secured by temporal desynchronization

A method of executing machine code using a microprocessor includes, for each datum D, computing a code Cusing a relationship C=Q(D)=P o F(D), where P is a predetermined function, Fis a function defined by the following relationship: F(D)=To . . . o To . . . o To T(D), and Tis αconditional transposition, configured by a secret parameter αr, that permutes two blocks Band Bof bits of the datum Don the basis of the value of the parameter αr. The method also includes computing a code Cusing the following relationship: C=C& C& . . . & C, where Cto Care the codes associated with data Dto Dcombined with one another by a Boolean operation D& D& . . . & Dwhere the '&' symbol designates the Boolean operation.

Method for the execution of a binary code by a microprocessor

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 binary code including the execution of an indirect load instruction which provokes the reading of a data line associated with an address obtained from the content of a destination register, then the construction of an initialization vector from the content of this data line, then the loading of this constructed initialization vector in a microprocessor, then the execution of an indirect branch instruction which provokes a branch directly to a first encrypted instruction line of a following basic block whose address is obtained from the content of the same destination register, then the decryption of the cryptogram of each encrypted instruction line of the following basic block using the initialization vector loaded in the microprocessor.

Method for executing a binary code of a function secured by a microprocessor

A method for executing a binary code includes for each item of data to be recorded: executing an algorithm for constructing a data line containing a cryptogram of this item of data constructed using an initialization vector ivassociated with an address @of the main memory using a relationship iv=F(@), where the function F, is a pre-programmed function that associates a different initialization vector ivwith each different address @of a main memory, and then recording this constructed data line in the main memory at the address @, where each instruction line of a basic block is constructed by executing the same construction algorithm as the one executed to construct the data line and using the same function F, the item of data for this purpose being taken to be equal to the instruction masked using a mask associated with this basic block.

Method for the execution of a binary code of a secure function by a microprocessor

A method for executing a binary code of a secure function includes obtaining a pointer containing: a first range of bits containing the address of a line of code, and a second, different range of bits containing an identifier of the pointer, storing the line of code, this line of code containing a first integrity tag constructed or encrypted using the identifier of the pointer, loading the line of code from the address contained in the first range of bits of the pointer, verifying the integrity of the loaded line of code by constructing a second integrity tag using the identifier of the pointer contained in the second range of bits of the pointer used to load it.

Method for executing a binary code of a secure function with a microprocessor

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 method including the loading into registers of a microprocessor of a code line recorded at an address @, and then calculating, with a securing hardware module, an initialization vector with the aid of a relation iv=F(@), where @is the address from which the code line was loaded, and then decrypting, with the securing hardware module, the code line loaded with the aid of the initialization vector calculated to obtain: a datum Dof its cryptogram, and a first error-detecting code, and then verifying, with the securing hardware module and with the aid of the first error-detecting code obtained, whether there exists an error in the datum Dor its cryptogram and, if such an error exists, triggering the signalling of an execution fault and, if such an error does not exist, inhibiting this signalling of an execution fault.

Growing community of inventors

Sassenage, France

Olivier Savry