Abstract: A method and apparatus are provided for modulating a binary source sequence including of a plurality of source words to generate modulated symbols. The method implements error-correction encoding of the plurality of source words, implementing one or more encoding modules, each implementing a separate error-correction code to generate a plurality of code words, the source words being encoded in series. The code words are interlaced to generate an interlaced sequence. The interlaced sequence is differentially modulated to generate modulated symbols. Each code word is broken down into at least one group with a number of bits equal to the base-2 logarithm of a number of states of a modulation implemented by the step of differentially modulating. The interlacing step distributes the groups such that two adjacent groups in the interlaced sequence belong to separate code words.

Abstract: The present invention is related to a decision-support system and method for providing with a score an object represented by a target item from a multidimensional space, said score being representative of the probability that the object satisfies a given binary property. The method and/or decision support-system may be performed in a computer environment comprising processing means connected to memory means.

Abstract: A method is provided for producing securing data for implementing a secured session between a first and at least a second entity based on a protocol for establishing secured sessions. The method includes setting up a third secured entity related to the first entity; generating at least a portion of the securing data within the third entity; and transmitting the securing data from the secured third entity to the first entity.

Abstract: A cryptography circuit protected against observation attacks comprises at least one register R providing a variable x masked by the mask m, the masked variable being encrypted by a first substitution box S -in a cyclic manner. The circuit also comprises a mask register M delivering at each cycle a mask mt, the transformation of m, the mask m being extracted from mt before being encrypted by a second substitution box S?, the new mask m? obtained on output from this box S? is transformed into a mask m?t before being stored in the mask register M. The transformation consists of a bijection or a composition law making it possible to reduce or indeed to cancel any high-order attack in accordance with a model of activity of the registers R and M. Cryptography circuits are protected against high-order observation attacks on installations based on masking.

Abstract: The present invention is related to a method for providing with a score an object represented by a target item from a multidimensional space, said score being representative of the probability that the object satisfies a given binary property, said method being performed in a computer environment comprising processing means connected to memory means, comprising the following steps: (a) providing and storing in the memory means data representative of a set of sample items from said multidimensional space, each sample item being associated with a multi-value label representative of the probability that an object represented by said sample item satisfies the given binary property; (b) storing in the memory means data representative of the target item; (c) with said processing means, generating and storing in said memory means data representative of an oriented binary tree with a given height, said binary tree being defined by a plurality of nodes having index values in relation with their position in the binary

Abstract: A cryptography circuit protected by masking, said circuit including means for encrypting binary words using at least one key krc, means for applying linear processing operations and nonlinear processing operations to said words and means for masking said words. The binary words are unmasked upstream of the nonlinear processing operations by using a mask kri and masked downstream of said processing operations by using a mask kr+1i, the masks kri and kr+1i being chosen from a set of masks that is specific to each instance of the circuit.

Abstract: A method is provided for decoding a signal received by a receiver including at least one reception antenna. The method includes: selecting, among at least two techniques available in the receiver, a decoding technique representative of a space/time encoding implemented upon transmission; and decoding the signal using the selected decoding technique. The selecting step takes into account at least one selection criterion.

Abstract: A method of decoding a data signal includes progressively constructing a decoding tree, implementing at least two iterations of the following steps: selecting at least one child node of a current node belonging to a selection interval; storing the child nodes in a first stack; deleting the current node from the first stack; selecting a new current node from the first stack; and if the new current node is a leaf node, storing the path between the root node and the leaf node, in the second stack, and deleting the leaf node from the first stack; otherwise, return to the step of selecting a child node for the new current node. Moreover, the method assigns a probability of likelihood to the bits of at least one symbol of the data signal, taking account of the paths stored in the second stack, and determines a probabilistic estimation of the signal.

Abstract: A cryptography circuit protected against observation attacks comprises at least one register R providing a variable x masked by the mask m, the masked variable being encrypted by a first substitution box S in a cyclic manner. The circuit also comprises a mask register M delivering at each cycle a mask mt, the transformation of m, the mask m being extracted from mt before being encrypted by a second substitution box S?, the new mask m? obtained on output from this box S? is transformed into a mask m?t before being stored in the mask register M. The transformation consists of a bijection or a composition law making it possible to reduce or indeed to cancel any high-order attack in accordance with a model of activity of the registers R and M. Cryptography circuits are protected against high-order observation attacks on installations based on masking.

Abstract: A method and apparatus are provided for modulating a binary source sequence including of a plurality of source words to generate modulated symbols. The method implements error-correction encoding of the plurality of source words, implementing one or more encoding modules, each implementing a separate error-correction code to generate a plurality of code words, the source words being encoded in series. The code words are interlaced to generate an interlaced sequence. The interlaced sequence is differentially modulated to generate modulated symbols. Each code word is broken down into at least one group with a number of bits equal to the base-2 logarithm of a number of states of a modulation implemented by the step of differentially modulating. The interlacing step distributes the groups such that two adjacent groups in the interlaced sequence belong to separate code words.

Abstract: A method and apparatus are provided for generating security data for implementing a secure session between a first and at least a second entity according to a secure session establishment protocol. Such a method includes: initializing a third secure entity connected to the first entity; generating at least a portion of the security data within the third entity; transmitting the generated security data from the secure third entity to the first entity; and transmitting at least a portion of the security data generated in the third secure entity to at least a previously initialized fourth secure entity connected to the third secure entity.

Abstract: A cryptography circuit, protected notably against information-leak observation attacks, comprises a functional key kc for executing a cryptography algorithm. It comprises a second key ki unique and specific to the circuit making it possible to protect by masking the functional and confidential key kc or a confidential implementation of the algorithm.

Abstract: A method for protecting a programmable logic circuit includes storing data file(s) used for the configuration of the programmable resources of the circuit in a non-volatile memory after having been encrypted. A decryption module internal to the circuit is responsible for decrypting the file(s) by using a secret key stored in the circuit, the decryption module being protected against attacks aiming to obtain the key during the decryption operation by implementing at least one countermeasure technique.

Abstract: A method of decoding a data signal includes progressively constructing a decoding tree, implementing at least two iterations of the following steps: selecting at least one child node of a current node belonging to a selection interval; storing the child nodes in a first stack; deleting the current node from the first stack; selecting a new current node from the first stack; and if the new current node is a leaf node, storing the path between the root node and the leaf node, in the second stack, and deleting the leaf node from the first stack; otherwise, return to the step of selecting a child node for the new current node. Moreover, the method assigns a probability of likelihood to the bits of at least one symbol of the data signal, taking account of the paths stored in the second stack, and determines a probabilistic estimation of the signal.

Abstract: A method is provided for decoding a signal received by a receiver including at least one reception antenna. The method includes: selecting, among at least two techniques available in the receiver, a decoding technique representative of a space/time encoding implemented upon transmission; and decoding the signal using the selected decoding technique. The selecting step takes into account at least one selection criterion.

Abstract: A method is provided for producing securing data for implementing a secured session between a first and at least a second entity based on a protocol for establishing secured sessions. The method includes setting up a third secured entity related to the first entity; generating at least a portion of the securing data within the third entity; and transmitting the securing data from the secured third entity to the first entity.