Abstract: A cryptographic circuit performs a substitution operation of a cryptographic algorithm. For each substitution operation of the cryptographic algorithm, a series of substitution operations are performed by the cryptographic circuit. One of the substitution operations of the series is a real substitution operation corresponding to the substitution operation of the cryptographic algorithm. One or more other substitution operations of the series are dummy substitution operations. A position of the real substitution operation in said series is selected randomly.

Abstract: The present disclosure relates to a method of fault detection in an application, by an electronic circuit, of a first function to a message, including the steps of generating, from the message, a non-zero even number N of different first sets, each including P shares; applying, to the P shares of each first set, one or a plurality of second functions delivering, for each first set, a second set including Q images; and cumulating all the images, starting with at most Q-1 images selected from among the Q images of a same second set.

Abstract: The present disclosure relates to a method for protecting a first data item applied to a cryptographic algorithm, executed by a processor, wherein said algorithm is a per-round algorithm, with each round processing contents of first, second and third registers, the content of the second register being masked, during first parity rounds, by the content of a fourth register and the content of the third register being masked, during second parity rounds, by the content of a fifth register.

Abstract: Cryptographic circuitry, in operation, performs a calculation on a first number and a second number. The performing of the calculation is protected by breaking the second number into a plurality of third numbers, a sum of values of the third numbers being equal to a value of the second number. The calculation is performed bit by bit for each rank of the third numbers. Functional circuitry, coupled to the cryptographic circuitry, uses a result of the calculation.

Abstract: A method and device for protecting encrypted data are disclosed. In an embodiment an integrated circuit includes a secure module including a first register containing a first mask and a second register containing masked data, the first mask and the masked data forming a secret key and a processor configured to generate a second mask and mask the secret key with the second mask when the secret key is not used for an encryption operation and during reception of a validation signal, wherein the first and second registers are disposed in the secure module so that the outputs of the registers are not simultaneously optically viewable.

Abstract: Systems and methods for protecting secret or secure information involved in generation of ciphered data by circuitry. The circuitry includes data paths and key paths that operate to perform cipher operations to generate a plurality of key shares and a plurality of data shares using a key and data as input. The data and the key may be masked by at least one mask. The plurality of key shares may be generated using the key and a first mask. The plurality of data shares are generated using key shares, the data, and a second mask.

Abstract: A calculation is performed on a first number and a second number. For each bit of the second number a first function is performed. The first function inputs include contents of a first register, contents of a second register and the first number. A result of the first function is placed in a third register. For each bit of the second number, a second function is performed which has as inputs contents of the third register and the contents of a selected one of the first and the second register according to a state of a current bit of the second number. A result of the second function is stored in the selected one of the first and second register.

Abstract: A cryptographic circuit performs a substitution operation of a cryptographic algorithm. For each substitution operation of the cryptographic algorithm, a series of substitution operations are performed by the cryptographic circuit. One of the substitution operations of the series is a real substitution operation corresponding to the substitution operation of the cryptographic algorithm. One or more other substitution operations of the series are dummy substitution operations. A position of the real substitution operation in said series is selected randomly.

Abstract: The disclosure concerns implementing, by a cryptographic circuit, a set of substitution operations of a cryptographic process involving a plurality of substitution tables. For each set of substitution operations of the cryptographic process, a series of sets of substitution operations are performed. One set of the series is a real set of substitution operations corresponding to the set of substitution operations of the cryptographic process. One or more other sets are dummy sets of substitution operations, each dummy set being based on a different permutation of said substitution tables.

Abstract: The disclosure concerns a method of protecting a calculation on a first number and a second number, including the steps of: generating a third number including at least the bits of the second number, the number of bits of the third number being an integer multiple of a fourth number; dividing the third number into blocks each having the size of the fourth number; successively, for each block of the third number: performing a first operation with a first operator on the contents of a first register and of a second register, and then on the obtained intermediate result and the first number, and placing the result in a third register; and for each bit of the current block, performing a second operation by submitting the content of the third register to a second operator with a function of the rank of the current bit of the third number, and then to the first operator with the content of the first or of the second register according to state “0” or “1” of said bit, and placing the result in the first or second re

Abstract: A cryptographic circuit performs a substitution operation of a cryptographic algorithm based on a scrambled substitution table. For each set of one or more substitution operations of the cryptographic algorithm, the circuit performs a series of sets of one or more substitution operations of which: one is a real set of one or more substitution operations defined by the cryptographic algorithm, the real set of one or more substitution operations being based on input data modified by a real scrambling key; and one or more others are dummy sets of one or more substitution operations, each dummy set of one or more dummy substitution operations being based on input data modified by a different false scrambling key.

Abstract: A cryptographic circuit performs a substitution operation of a cryptographic algorithm. For each substitution operation of the cryptographic algorithm, a series of substitution operations are performed by the cryptographic circuit. One of the substitution operations of the series is a real substitution operation corresponding to the substitution operation of the cryptographic algorithm. One or more other substitution operations of the series are dummy substitution operations. A position of the real substitution operation in said series is selected randomly.

Abstract: The present disclosure relates to a method of fault detection in an application, by an electronic circuit, of a first function to a message, including the steps of generating, from the message, a non-zero even number N of different first sets, each including P shares; applying, to the P shares of each first set, one or a plurality of second functions delivering, for each first set, a second set including Q images; and cumulating all the images, starting with at most Q-1 images selected from among the Q images of a same second set.

Abstract: In an embodiment, a circuit includes a supply terminal, a reference terminal, a logic circuit coupled between the supply terminal and the reference terminal, and an auxiliary circuit coupled to the logic circuit. The auxiliary circuit includes a plurality of switches configured to be controlled to produce random criterions. Each random criterion causes, on each transition of an output signal of the logic, an attenuation of a current flowing between a supply terminal of the circuit and a reference terminal of the circuit; or an increase of the current flowing between the supply terminal of the circuit and the reference terminal of the circuit; or an additional current flowing through the logic circuit on a current path not passing through the supply terminal; or no change in the current flowing between the supply terminal of the circuit and the reference terminal of the circuit.

Abstract: An iterative calculation is performed on a first number and a second number, while protecting the iterative calculation against side-channel attacks. For each bit of the second number, successively, an iterative calculation routine of the bit of the second number is determined. The determination is made independent of a state of the bit. The determined iterative calculation routine of the bit is executed. A result of the iterative calculation is generated based on a result of the execution of the determined iterative calculation routine of a last bit of the second number.

Abstract: The supply voltage for a module of an integrated circuit managed to support protection against side channel attacks. Upon startup of the integrated circuit, one action from the following actions is selected in response to a command: supplying the module with the supply voltage having a fixed value that is selected from a plurality of predetermined values, or varying the value of the supply voltage in time with a pulsed signal.

Abstract: Systems and methods for protecting secret or secure information involved in generation of ciphered data by circuitry. The circuitry includes data paths and key paths that operate to perform cipher operations to generate a plurality of key shares and a plurality of data shares using a key and data as input. The data and the key may be masked by at least one mask. The plurality of key shares may be generated using the key and a first mask. The plurality of data shares are generated using key shares, the data, and a second mask.

Abstract: A method and device for protecting encrypted data are disclosed. In an embodiment an integrated circuit includes a secure module including a first register containing a first mask and a second register containing masked data, the first mask and the masked data forming a secret key and a processor configured to generate a second mask and mask the secret key with the second mask when the secret key is not used for an encryption operation and during reception of a validation signal, wherein the first and second registers are disposed in the secure module so that the outputs of the registers are not simultaneously optically viewable.

Abstract: Cryptographic circuitry, in operation, performs a calculation on a first number and a second number. The performing of the calculation is protected by breaking the second number into a plurality of third numbers, a sum of values of the third numbers being equal to a value of the second number. The calculation is performed bit by bit for each rank of the third numbers. Functional circuitry, coupled to the cryptographic circuitry, uses a result of the calculation.

Abstract: An electronic device includes a logic circuit and an auxiliary circuit. The logic circuit includes a first terminal coupled to a supply voltage terminal, a second terminal intended coupled to a reference voltage terminal and an output terminal configured to deliver a signal in a high state or a low state. The auxiliary circuit is coupled between the first terminal and the second terminal and is configured to randomly generate or not generate an additional current between the first terminal and the second terminal on each change of state of the signal on the output terminal.