Abstract: There is provided a device for protecting the execution of a cryptographic operation from attacks, the cryptographic operation being implemented by a cryptographic algorithm, the cryptographic operation comprising at least one modular operation between a main base (m) representing a data block and at least one scalar (d) in at least one finite starting group. The device is configured to determine at least one intermediary group (E?) different from the at least one starting group (E), the number of intermediary groups being equal to the number of starting groups E. The device is further configured to determine at least one final group (E?) from the at least one starting group E and the at least one intermediary group E?. The base m being mapped to an auxiliary element (x) in the at least one intermediary group and to an auxiliary base (m?) in the at least one final group E?.

Abstract: There is provided a device for protecting the execution of a cryptographic operation from attacks, the cryptographic operation being implemented by a cryptographic algorithm, the cryptographic operation comprising at least one modular operation between a main base (m) representing a data block and at least one scalar (d) in at least one finite starting group. The device is configured to determine at least one intermediary group (E?) different from the at least one starting group (E), the number of intermediary groups being equal to the number of starting groups E. The device is further configured to determine at least one final group (E?) from the at least one starting group E and the at least one intermediary group E?. The base m being mapped to an auxiliary element (x) in the at least one intermediary group and to an auxiliary base (m?) in the at least one final group E?.

Abstract: There is provided a device or a method for executing an operation of a cryptographic scheme, the operation being applied to a given state of a data block of original data, the operation being defined in a basis ring corresponding to the quotient of a starting ring by a basis ideal generated by at least one element of the starting ring. The operation is executed from a state derived from the current state of the data block, in at least one reference ring, which provides a reference value for each reference ring, each reference ring being the quotient of the starting ring by a reference ideal.

Abstract: The subject of the invention is a countermeasure method for an electronic component implementing a public-key cryptography algorithm on an elliptic curve E defined over a field and comprising an iterative scalar multiplication operation making it possible to obtain a point [k]P on the basis of a point P of the curve E and of an integer k that must remain secret, the electrical consumption of the electronic component being dependent on the value taken by at least one so-called critical point used during said operation to iteratively determine the point [k]P.

Abstract: There is provided a modular multiplication device for performing a multiplication of a first multiplicand and a second multiplicand modulo a given modulus, each of the multiplicand comprising a given number of digits, each digit having a given word size.

Abstract: There is provided a device for executing an operation of a cryptographic scheme, the operation being applied to a given state of a data block of original data, the operation being defined in a basis ring corresponding to the quotient of a starting ring by a basis ideal generated by at least one element of the starting ring, the device comprising: a first execution unit (120) configured to execute the operation from a state derived from the current state of the data block, in at least one reference ring, which provides a reference value for each reference ring, each reference ring being the quotient of the starting ring by a reference ideal, and a second execution unit (122) configured to execute the operation from the state derived from the current state of the data block in at least one extended ring corresponding to one or more reference rings, which provides at least one extension value for each extended ring, each extended ring corresponding to one or more reference ring being the quotient of the start

Abstract: There is provided a modular multiplication device for performing a multiplication of a first multiplicand and a second multiplicand modulo a given modulus, each of the multiplicand comprising a given number of digits, each digit having a given word size.

Abstract: The subject of the invention is a countermeasure method for an electronic component implementing a public-key cryptography algorithm on an elliptic curve E defined over a field and comprising an iterative scalar multiplication operation making it possible to obtain a point [k]P on the basis of a point P of the curve E and of an integer k that must remain secret, the electrical consumption of the electronic component being dependent on the value taken by at least one so-called critical point used during said operation to iteratively determine the point [k]P.