Abstract:
A method of detecting a cold-boot attack on an integrated circuit, including the steps of: periodically sampling a signal delivered by at least one ring oscillator; and verifying that the proportion of states “1” and of states “0” of the result of the sampling is within a range of values.
Abstract:
A method of protecting a modular exponentiation calculation executed by an electronic circuit using a first register and a second register, successively comprising, for each bit of the exponent: a first step of multiplying the content of one of the registers, selected from among the first register and the second register according to the state of the bit of the exponent, by the content of the other one of the first and second registers, placing the result in said one of the registers; a second step of squaring the content of said other one of the registers by placing the result in this other register, wherein the content of said other one of the registers is stored in a third register before the first step and is restored in said other one of the registers before the second step.
Abstract:
A device includes one or more registers and circuitry. The circuitry subjects a key having a number of bits to a first function which takes a selection value into account, generating a result having a number of bits which is twice the number of bits of the key, and stores the result in the one or more registers. In response to a call for the key, the circuitry subjects the result stored in the one or more registers to a second function which takes the selection value into account to generate a response having a same value as the key.
Abstract:
A method for protecting a ciphering algorithm executing looped operations on bits of a first quantity and on a first variable initialized by a second quantity, wherein, for each bit of the first quantity, a random number is added to the state of this bit to update a second variable maintained between two thresholds.
Abstract:
A method of detecting a cold-boot attack on an integrated circuit, including the steps of: periodically sampling a signal delivered by at least one ring oscillator; and verifying that the proportion of states “1” and of states “0” of the result of the sampling is within a range of values.
Abstract:
A method of detecting a cold-boot attack on an integrated circuit including the steps of: transferring, into a first volatile memory of the integrated circuit, a pattern stored in a non-volatile memory of the circuit; periodically causing a switching down and a switching up of the first volatile memory; and verifying that the number of bits having switched state is within a range of values.
Abstract:
A method for protecting a volatile memory against a virus, wherein: rights of writing, reading, or execution are assigned to certain areas of the memory; and a first list of opcodes authorized or forbidden as a content of the areas is associated with each of these areas.
Abstract:
A method for detecting a fault injection in a random number generation circuit, wherein a bit pattern is mixed to a bit stream originating from a noise source and the presence of this pattern is detected in a signal sampled downstream of the mix.
Abstract:
A method of protecting a circuit from attacks aiming to discover secret data used during the execution of a cryptographic calculation by the circuit, by, executing a transformation calculation implementing a bijective transformation function, receiving as input a secret data, and supplying a transformed data, executing a cryptographic calculation receiving as input a data to process and the transformed data, and executing an inverse transformation calculation receiving as input the result of the cryptographic calculation, and supplying a result that the cryptographic calculation would have supplied if it had been applied to the data to process and directly to the secret data, the data to process belong to a stream of a multiplicity of data, the transformed data being supplied as input to the cryptographic calculation for all the data of the stream.
Abstract:
A method of protecting a modular exponentiation calculation executed by an electronic circuit using a first register and a second register, successively comprising, for each bit of the exponent: a first step of multiplying the content of one of the registers, selected from among the first register and the second register according to the state of the bit of the exponent, by the content of the other one of the first and second registers, placing the result in said one of the registers; a second step of squaring the content of said other one of the registers by placing the result in this other register, wherein the content of said other one of the registers is stored in a third register before the first step and is restored in said other one of the registers before the second step.