Abstract: The present invention relates to a method for encryption or decryption of a data block from a secret key, wherein the method comprises: generating a first round key kr dependent on the secret key, selecting each of a first mask (?br) and a second mask (?br+1) in a set consisting of a mask of bits all at one and a mask of all zero bits, calculating a first masked key kr? from the first round key kr and the first mask (?br) as follows: kr?=kr?(?br) wherein ? is an exclusive disjunction, executing a first encryption round applied to two first data dependent on the data block, by means of the first masked round key kr? so as to produce two second data, after producing the first masked key kr?, generating a second round key kr+1 dependent on the secret key, calculating a second masked key kr+1? from the second round key kr+1 and the second mask (?br+1) as follows: kr+1?=kr+1?(?br+1), calculating two third data Lrbr+1, Rrbr+1 as follows: Rrbr+1=Rrbr?(?br?1)?(?br) Lrbr+1=Lrbr?(?br?1)?(?br) and executing a secon

Abstract: The present invention relates to a method for symmetrical encryption or decryption of a data block from a secret key (K), the method comprising steps of: permutation (100) of at least one portion of the secret key (K) by means of a first permutation table (PC1?) so as to produce initial data, execution of several iterations, an iteration comprising steps of: rotation (102) of data dependent on the initial data so as to produce shifted data, permutation (104) of the shifted data by means of a second permutation table (PC2?) so as to produce a round key, execution of a plurality of encryption rounds (200) from the data block, an encryption round (200) using one of the round keys, generation of at least one of the permutation tables (PC1?, PC2?), the generation comprising determination of at least one function (F, G) variable from one encryption or decryption to another, composition of said function (F, G) with a predetermined permutation table (PC1, PC2), application of the inverse of said function (F,

Abstract: The invention relates to a cryptographic processing method comprising multiplication of a point P of an elliptic curve on a Galois field by a scalar k, the multiplication comprising steps of: storing, in a first register, a zero point of the Galois field, executing a loop comprising at least one iteration comprising steps of: selecting a window of w bits in the non-signed binary representation of the scalar k, w being a predetermined integer independent of the scalar k and strictly greater than 1, calculating multiple points of P being each associated with a bit of the window and of the form ±2iP, adding or not in the first register of multiple points stored, depending of the value of the bit of the window with which the multiple points are associated, wherein the loop ends once each bit of the non-signed binary representation of the scalar k has been selected, returning a value stored in the first register.

Abstract: A method for determining the presence of a human being, comprising: measuring (S6) a movement (MOV) of a first device (4) by a sensor (44) of said first device (4), determining the presence of a human being on the basis of the measured movement (MOV).

Abstract: Provided is a method for optimising memory writing in a device implementing a cryptography module and a client module calling functions implemented by the cryptography module. The device includes a random access memory including a first memory zone that is secured and dedicated to the cryptography module and a second memory zone dedicated to the client module. When the client module calls a series of functions implemented by the cryptography module including a first function and at least one second function, with each second function executed following the first function or from a further second function and providing a runtime result added to a runtime result of the preceding series function, each runtime result is added to a value contained in a buffer memory allocated in the first memory. The buffer memory value is copied to the second memory zone following the execution of the last function of the series.

Abstract: Intrusion detection systems dedicated to an operating system, and an intrusion detection system in a device implementing at least a first operating system and a second operating system are provided. The intrusion detection systems includes: a listening module configured to be executed in the first operating system in order to listen to the activity of this first operating system; a collecting module configured to be executed in the first operating system in order to collect data characterizing the activity of the first operating system; and an analysis and detection module configured to be executed in the second operating system in order to analyze the data collected in the first operating system and detect a suspicious activity in the first operating system depending on the analysis.

Abstract: Generation of a message m of order ?(n) for a test of the integrity of the generation of a pair of cryptographic keys within the multiplicative group of integers modulo n=p·q, including: —key pair generation including, to generate p and q: a random selection of candidate integers; and a primality test; —a first search of the multiplicative group of integers modulo p for a generator a; —a second search of the multiplicative group of integers modulo q for a generator b; —a third search for a number y, as message m, verifying: 1???n?1, where ?=a mod p and ?=b mod q, the first or second search being performed during the primality test.

Abstract: The invention relates to a cryptographic processing method comprising multiplication of a point P of an elliptic curve on a Galois field by a scalar k, the multiplication comprising steps of: storing, in a first register, a zero point of the Galois field, executing a loop comprising at least one iteration comprising steps of: selecting a window of w bits in the non-signed binary representation of the scalar k, w being a predetermined integer independent of the scalar k and strictly greater than 1, calculating multiple points of P being each associated with a bit of the window and of the form ±2iP, adding or not in the first register of multiple points stored, depending of the value of the bit of the window with which the multiple points are associated, wherein the loop ends once each bit of the non-signed binary representation of the scalar k has been selected, returning a value stored in the first register.

Abstract: The present invention relates to a method for symmetrical encryption or decryption of a data block from a secret key (K), the method comprising steps of: permutation (100) of at least one portion of the secret key (K) by means of a first permutation table (PC1?) so as to produce initial data, execution of several iterations, an iteration comprising steps of: rotation (102) of data dependent on the initial data so as to produce shifted data, permutation (104) of the shifted data by means of a second permutation table (PC2?) so as to produce a round key, execution of a plurality of encryption rounds (200) from the data block, an encryption round (200) using one of the round keys, generation of at least one of the permutation tables (PC1?, PC2?), the generation comprising determination of at least one function (F, G) variable from one encryption or decryption to another, composition of said function (F, G) with a predetermined permutation table (PC1, PC2), application of the inverse of said function (F,

Abstract: The present invention relates to a method for encryption or decryption of a data block from a secret key, wherein the method comprises: generating a first round key kr dependent on the secret key, selecting each of a first mask (?br) and a second mask (?br+1) in a set consisting of a mask of bits all at one and a mask of all zero bits, calculating a first masked key kr? from the first round key kr and the first mask (?br) as follows: k?=kr?(?br) wherein ? is an exclusive disjunction, executing a first encryption round applied to two first data dependent on the data block, by means of the first masked round key kr? so as to produce two second data, after producing the first masked key kr?, generating a second round key kr+i dependent on the secret key, calculating a second masked key kr+1? from the second round key kr+i and the second mask (?br+1) as follows: kr+1? =kr+1 ED (?br+1), calculating two third data Lrbr+1, Rrbr+1 as follows: Rrbr+1=Rrbr?(?br?1)?(?br) Lrbr+1=Lrbr?(?br?1)?(?br) and executing

Abstract: Provided is a method for optimising memory writing in a device implementing a cryptography module and a client module calling functions implemented by the cryptography module. The device includes a random access memory including a first memory zone that is secured and dedicated to the cryptography module and a second memory zone dedicated to the client module. When the client module calls a series of functions implemented by the cryptography module including a first function and at least one second function, with each second function executed following the first function or from a further second function and providing a runtime result added to a runtime result of the preceding series function, each runtime result is added to a value contained in a buffer memory allocated in the first memory. The buffer memory value is copied to the second memory zone following the execution of the last function of the series.

Abstract: Method of integrity verification of cryptographic key pairs, the method including an integrity test with: at least one first step implementing one of the private and public keys and an initial test datum, the first step making it possible to generate a first result, at least one second step implementing at least the first result and the key not used during the at least one first step, the second step making it possible to generate a second result, and a comparison of the second result and of the initial test datum, characterized in that the test is re-executed upon each positive comparison, and in that the test is executed at least 2 times.

Abstract: Method of integrity verification of public and private cryptographic key pairs in the additive group of integers modulo n, with n being the product of two prime numbers p and q, the method including the following steps: of computation (201), on the basis of the number n, of a public exponent e of the public key, and of a private exponent d of the private key, of two candidate factors p? and q? corresponding respectively to the numbers p and q, of verification (206) so as to verify the consistency of the private exponent with respect to the public exponent and to the number n, the verification step involving the candidate factors.

Abstract: Generation of a message m of order ?(n) for a test of the integrity of the generation of a pair of cryptographic keys within the multiplicative group of integers modulo n=p·q, including: —key pair generation including, to generate p and q: a random selection of candidate integers; and a primality test; —a first search of the multiplicative group of integers modulo p for a generator a; —a second search of the multiplicative group of integers modulo q for a generator b; —a third search for a number y, as message m, verifying: 1???n?1, where ?=a mod p and ?=b mod q, the first or second search being performed during the primality test.

Abstract: Intrusion detection systems dedicated to an operating system, and an intrusion detection system in a device implementing at least a first operating system and a second operating system. The intrusion detection systems includes: a listening module (1110) configured to be executed in the first operating system in order to listen to the activity of this first operating system; a collecting module (1120) configured to be executed in the first operating system in order to collect data characterizing the activity of the first operating system; and an analysis and detection module (1150) configured to be executed in the second operating system in order to analyze the data collected in the first operating system and detect a suspicious activity in the first operating system depending on the analysis.

Abstract: The method serves to verify the validity of an electronic parking ticket stored in an electronic entity. The method includes a step of securely obtaining from the electronic ticket specific data that is specific to said electronic entity or to the vehicle in which it is installed, and a step of making available at least a portion of said specific data on an inspection device. The method enables a dishonest attack of the “man-the-middle” type to be detected.

Abstract: Method of integrity verification of cryptographic key pairs, the method including an integrity test with: at least one first step implementing one of the private and public keys and an initial test datum, the first step making it possible to generate a first result, at least one second step implementing at least the first result and the key not used during the at least one first step, the second step making it possible to generate a second result, and a comparison of the second result and of the initial test datum, characterized in that the test is re-executed upon each positive comparison, and in that the test is executed at least 2 times.

Abstract: Method of integrity verification of public and private cryptographic key pairs in the additive group of integers modulo n, with n being the product of two prime numbers p and q, the method including the following steps: of computation (201), on the basis of the number n, of a public exponent e of the public key, and of a private exponent d of the private key, of two candidate factors p? and q? corresponding respectively to the numbers p and q, of verification (206) so as to verify the consistency of the private exponent with respect to the public exponent and to the number n, the verification step involving the candidate factors.

Abstract: The method serves to verify the validity of an electronic parking ticket stored in an electronic entity. The method includes a step of securely obtaining from the electronic ticket specific data that is specific to said electronic entity or to the vehicle in which it is installed, and a step of making available at least a portion of said specific data on an inspection device. The method enables a dishonest attack of the “man-the-middle” type to be detected.