Abstract: A method for decrypting the encrypted messages sent by a transmission device to a first electronic device associated with a first trusted authority and to a second electronic device (ME). In one embodiment, first and second tokens are generated and exchanged, respectively, by the first and second electronic devices, which then generate a joint decryption key in order to decrypt the encrypted message.

Abstract: A method for generating a digital signature includes calculating a first magnitude representative of the inverse of a random number raised to the power two; obtaining a first element of the digital signature by executing scalar multiplication between an established point of the elliptic curve and the random number; obtaining a second magnitude by executing modular multiplication, with modulus corresponding to the established elliptic curve's order between the first magnitude and the secret encryption key; obtaining a third magnitude by executing a modular multiplication, with modulus corresponding to the established elliptic curve's order between the random number and the secret encryption key; obtaining a first addend of a second element of the digital signature by executing a modular multiplication, with modulus corresponding to the established elliptic curve's order between the second magnitude and the third magnitude; and generating a second element of the digital signature based on the first addend.

Abstract: A computing method and circuit for computing a modular operation with at least one operand having a binary representation. Iteratively for each bit of this operand, doubling the value of an intermediate result stored in a first memory element by shifting the bits of the intermediate result towards the most significant bit and, while the most significant bit of the intermediate result is one, updating this intermediate result by subtracting a modulus stored in a second memory element.

Abstract: Cryptographic methods are known that involve the computation of a non-degenerate bilinear mapping of first and second elements one of which comprises a secret of a first entity. For a mapping implemented as, for example, a Tate pairing, the mapping is computable by applying a predetermined function to the first and second elements and then exponentiating the result with a known exponent. Improvements in respect of computational loading, size of output, and security are enabled for the first party by arranging for the first entity to carry out only part of the mapping, a second entity being used to complete computation of the mapping. Cryptographic applications using these improvements are also disclosed.

Abstract: A method decrypts the encrypted messages sent by a transmission device to a first electronic device associated with a first trusted authority and to a second electronic device. In one embodiment, first and second tokens are generated and exchanged, respectively, by the first and second electronic devices, which then generate a joint decryption key in order to decrypt the encrypted message.

Abstract: A method for decrypting the encrypted messages sent by a transmission device to a first electronic device associated with a first trusted authority and to a second electronic device (ME). In one embodiment, first and second tokens are generated and exchanged, respectively, by the first and second electronic devices, which then generate a joint decryption key in order to decrypt the encrypted message.

Abstract: A method and an element for ciphering with an integrated processor data to be stored in a memory, including applying to each data block to be ciphered a ciphering algorithm which is a function of at least one key specific to the integrated circuit, and before applying the ciphering algorithm thereto, combining the data block to be ciphered with the result of a function of the storage address of the ciphered block in the memory, and/or of combining the key with the result of a function of the storage address of the ciphered block in the memory and of a digital quantity different from the ciphering key.

Abstract: A process for transmitting a message between a first electronic device and a second electronic device of an energy distribution network is described. The process includes generating, by the first electronic device, a first data encryption key identifying the second electronic device on the basis of a main data encryption key and an identification code of the second electronic device. The process further includes generating, by the first electronic device and the second electronic device, a communication key on the basis of said first data encryption key and a reference datum.

Abstract: A method establishes a communication between a first electronic device associated with a first trusted authority and a second electronic device. The method includes: making a first key available to the first device for the communication between the first authority and the first device. A second trusted authority, associated with the second device and distinct and autonomous with respect to the first authority, generates a second key in order to communicate with the second device. Furthermore, the method includes: making the second key available to the second device; and providing the first and second devices with a communication key, to be used communication between the first and second devices, through at least one of the first and second authorities.

Abstract: A method pairs electronic equipment, particularly, in a wireless network system. The method includes: providing first and second wireless electronic equipment to be paired which store a first and a second public key, respectively, and providing a user with a wireless portable electronic device which stores a third public key. Then, the portable electronic device transmits the third public key in turn to the first and second electronic equipment, and receiving from the first and second equipment the first and second public keys, respectively. Moreover, the portable electronic device calculates first and second numbers starting from the first and second public keys, respectively. The same first and second numbers is independently calculated by the first and second electronic equipment, respectively, starting from the third public key and representing secret numbers shared between the portable device and the first and second electronic equipment.

Abstract: A method of establishing an encrypted communication by using keys between a first electronic device associated with a first trusted authority and a second electronic device, including generating a first secret key associated with the first device for the management of the communication, generating, at least in part by the first authority, a second secret key associated with the second device for the management of the communication. The method includes generating the first key at least in part by a second trusted authority associated with the second device that is distinct and autonomous from the first authority. Alternatively, the generation of the first key is performed, at least in part, by the second device passing through the second trusted authority.

Abstract: A method for implementing one-to-one binary functions defined on the Galois field GF(28) is very useful for forming fast and low power hardware devices regardless of the binary function. The method includes decoding an input byte for generating at least one bit string that contains only one active bit, and logically combining the bits of the bit string according to the binary function for generating a 256-bit string representing a corresponding output byte. The 256-bit string is then encoded in a byte for obtaining the output byte.

Abstract: An encoding/decoding apparatus comprises a central processing unit and an encryption/decryption accelerator coupled to the central processing unit. The accelerator comprises an input for input data to be encrypted/decrypted, an arithmetic logic unit coupled to said input for performing selectable operations on data obtained from said input data and an output for encrypted/decrypted data coupled to said arithmetic logic unit.

Abstract: A method for implementing one-to-one binary functions defined on the Galois field GF(28) is very useful for forming fast and low power hardware devices regardless of the binary function. The method includes decoding an input byte for generating at least one bit string that contains only one active bit, and logically combining the bits of the bit string according to the binary function for generating a 256-bit string representing a corresponding output byte. The 256-bit string is then encoded in a byte for obtaining the output byte.