Abstract: A countermeasure method in an electronic component using a secret key algorithm K on an input message M executes an operation OPN(D) on input data D. A random value, of one first random information U, is generated that is of identical size as the input information D. A second random information V, is calculated by performing an exclusive OR operation between the input information and the first random information U. The operation OPN or the sequence of operations are successively executed on the first input information U and to the second random information V, supplying respectively a first random result OPN(U) and a second random result OPN(V).

Abstract: The invention relates to an ocular device which permits the avoidance of the phenomenon of photophobia and the method for production thereof. The device comprises one or more chromophores which absorb light in the wavelengths between 400 and 575 nm (blue-green light) and which are dispersed, after the placement in or on the eye, in the surrounding body fluids in several weeks to several months depending on the concentration of the chromophores. The device is produced by conditioning of the non-colored ocular device in an aqueous solution of the chromophore(s) in the shade.

Abstract: The invention relates to a method for producing a biocompatible crosslinked gel consisting in crosslinking a determined quantity of at least one type of liquid biocompatible polymer by adding a quantity of crosslinking agent, in carrying out a crosslinking reaction, in adding an additional quantity of liquid polymer whose molecular mass is greater than 500,000 Da, in solving the reaction mixture in such a way that the total concentration of the liquid polymer is reduced, in crosslinking and in stopping the crosslinking reaction by removing the crosslinking agent. The inventive gel and the use thereof are also disclosed.

Abstract: The invention relates to a method for secure data transmission in connections between two functional modules of an electronic unit. A first module of a message of k bits in a word code of n bits is injection coded with a constant Hamming weight of w. The word of code is transmitted to a second module. An error signal is generated when the Hamming weight of the word of code of n bits, received by the second module, is different from w. In the absence of error, the code word is decoded, where k, w and n are whole numbers. The invention further relates to a corresponding electronic circuit.

Abstract: The present invention concerns an anti-SPA modular exponentiation algorithm in an electronic component using a public key ciphering algorithm. A pair of registers and an indicator are used to provide symmetrical processing of bits in the algorithm, so that the values of individual bits cannot be determined from power consumption.

Abstract: A complex matrix is constituted by at least one biocompatible polymer of natural origin, cross linked and to which are grafted small chains of a molecular weight less than 50,000 Da with an amount of grafting of 10 to 40%, as well as a process for preparation of a biocompatible matrix that is partly degradable, constituted by at least one polymer of natural origin, consisting: on the one hand, grafting small chains of molecular weight less than 10,000 Da, with a grafting amount of 10 to 40%, on the other hand, cross linking the principal polymer chains to create a homogeneous matrix.

Abstract: The invention concerns a countermeasure method in an electronic component using a secret key K cryptographic algorithm with sixteen computing cycles to supply an encrypted message (C) from an input message (M), each cycle using first means TC0 to supply an output information from an input information, Said method consists in applying by selection a sequence with the first means or another sequence with other means TC1, TC2 to a group G1 comprising the first three cycles at least and another group G4 comprising the last three cycles at least. Whatever the sequence, the output result of the last cycle of each group is the same for the same input message (M).

Abstract: An electronic component uses a secret key cryptographic algorithm that employs several successive computing cycles to supply final output data from initial input data applied at the first cycle. A first random value is applied to a computation conducted for each cycle, to obtain unpredictable output data. A second random value as also applied to the initial input data that is used for the input of the first cycle.

Abstract: A method for securing electronic device processes against attacks (e.g. side channel attacks) during the processing of sensitive and/or confidential data by a Central Processing Unit (CPU) to the volatile memory (e.g. RAM) of an electronic device such as, for example, a smart card, a PDA or a cellular phone is described herein. The method involves the storage of the confidential data to a dynamically and randomly assigned memory location, thereby rendering more difficult the analysis and subsequently the attacks (e.g. side channel attacks).

Abstract: The invention concerns microprocessor cards and, in such cards, various devices for hiding operations performed in the card against fraudulent breaches by analysing the current consumed. The invention is characterised in that it consists in adding in the card a device (20) modifying the consumed current, either by averaging it by integration, or by adding thereto random values by a random signal generator (28) so as to hide the operations performed. In another embodiment, it consists in carrying out simultaneously an operation for making secure and writing in an EEPROM memory, the latter generating chaotic current variations which hide the operation to be made secure.

Abstract: The present invention concerns an anti-SPA (from the English “Simple Power Attack”) modular exponentiation algorithm in an electronic component using a public key ciphering algorithm.