Abstract: The invention presents a process for obtaining candidate reference data to compare to a data to be identified, implemented in a system comprising a client unit and a storage server comprising two databases, in which: —the first database comprises indexed memory blocks each comprising a corresponding encrypted indexed reference data, and —the second database comprises memory blocks indexed by all possible hash values obtained by a plurality of k indexed hash functions, and wherein each block contains a list of the indexes of the reference data which hashing by one of said hash function results in the hash value corresponding to said block, said process comprising the steps during which: —the client unit hashes the data to be identified with each of the plurality of hash functions, and reads the k memory blocks of the second database corresponding to the hash values thus obtained, the client unit identifies indexes contained in at least t out of k read memory blocks, and —the client unit reads the memory blocks

Abstract: The invention relates to a method for signing a message (m), implemented by processing means of a user device of a member (Mi) belonging to a group of members (G), said user device having a secret signature key (ski), said method including a step of generating (E301) a group signature (?) for the message (m), enabling said member (Mi) to prove his membership in the group (G), and a step of generating (E302) a pseudonym (nymij) identifying the member (Mi) within a domain (Dj) of a service provider (SPj), said domain including a set of terminals in communication with a server of said service provider, said signature (?) being designed such that said member (Mi) can prove, by signing the message (m), his knowledge of said secret signature key without disclosing it, said group signature (?) being designed such that the membership of the member (Mi) in the group is verifiable independently from the pseudonym (nymij), said pseudonym and said signature being a function of a portion (xi) of said secret signature k

Abstract: The invention relates to a method of signature with pseudonym ? of a message m by a user device storing a secret signature key sk dependent at least on a first part of key f, on a second part of key x and on a third part of key A equal to (g1hf)1/(x+y) and comprising the following steps: —generation of a pseudonym nym equal to hf dpkx, with dpk a public domain parameter, —determination of random numbers a, r_a, r_f, r_x, r_b, r_d, —calculation of signature coefficients R1 equal to hr_Jdpkr_x, R2 equal to nymr_ah?r_ddpk?r_b, R3 equal to Zr_x Va?r_x?r_f?r_b W?r_a, with Z, V and W respectively equal to e(A, g2), e(h, g2) and e(h,w), —obtaining of a first signature parameter T equal to Aha, —calculation of a second signature parameter c by applying a cryptographic hash function H, to the public domain parameter dpk, to the pseudonym nym, to the first signature parameter T, to the signature coefficients R1, R2, R3 and to the message m, —calculation of signature parameters s_f, s_x, s_a, s_b, s_d, respectively equa

Abstract: The invention relates to a processing method, including the calculation of one function between a datum to be compared and a reference datum. The function can be written in the form of a sum of: a term that depends on the datum to be compared, a term that depends on the reference datum, and a polynomial, such that all the monomials of the polynomial include at least one coordinate of each datum. The method includes an initialization step including: generating masking data; scrambling reference data by means of a server unit on the basis of said masking data; and calculating, by means of a client unit, the term of the function that depends on the datum to be compared.

Abstract: The invention is about an identification process of an individual or object, in a system comprising a control server and a management server of a database comprising N indexed data of N stored individuals, in which, to identify the individual or object, its datum is compared to each of the N data of the base.

Abstract: A method of secure distributed storage on N servers and a secure access method to confidential data stored in a secure and distributed manner on N servers are provided. Additionally, distributed storage, devices, systems, computer programs and storage medium are provided for the implementation of such methods.

Abstract: The invention relates to a method of signature with pseudonym ? of a message m by a user device storing a secret signature key sk dependent at least on a first part of key f, on a second part of key x and on a third part of key A equal to (g1hf)1/(x+y) and comprising the following steps: —generation of a pseudonym nym equal to hfdpkx, with dpk a public domain parameter, —determination of random numbers a, r_a, r_f, r_x, r_b, r_d, —calculation of signature coefficients R1 equal to hr_Jdpkr_x, R2 equal to nymr_ah?r_ddpk?r_b, R3 equal to Zr_xVa?r_x?r_f?r_bW?r_a, with Z, V and W respectively equal to e(A, g2), e(h, g2) and e(h,w), —obtaining of a first signature parameter T equal to Aha, —calculation of a second signature parameter c by applying a cryptographic hash function H, to the public domain parameter dpk, to the pseudonym nym, to the first signature parameter T, to the signature coefficients R1, R2, R3 and to the message m, —calculation of signature parameters s_f, s_x, s_a, s_b, s_d, respectively equal t

Abstract: The invention relates to a method and system for managing and checking different identity data relating to a person. According to the invention, a derived-identity management server generates for the person at least part of the identity data with which said person can be authenticated in relation to a service provider for the derived-identity domain, on the basis of information derived from identity data from parent domains. The identity data generation processing ensures that no link can be established from two authentications in two separate domains in the absence of link information. If necessary, said link information is transmitted by a parent domain to a derived-identity server so that the latter establishes the link between the identity data of the derived-identity domain and the identity data of the parent domain, e.g. for the cascade revocation of a person from various domains.

Abstract: The invention relates to a secure method of processing data in which method is implemented the evaluation of a function that may be written as a linear combination of sub-functions with two binary inputs, in which a client and a server each possess a binary code, comprising n indexed bits, the method comprising the evaluation of the function with the binary codes of the client and of the server as inputs, without one of the client or the server obtaining information about the code of the other, the method being characterized in that it comprises the following steps: —the server randomly generates n indexed values and calculates the linear combination of these values with the same linear combination as that applied to the sub-functions to obtain the function, —the client implements, for each bit of his binary code, a technique of unconscious transfer to obtain from the server an intermediate data item comprising the randomly generated value of same index as the bit of the code of the client, increased by the v

Abstract: The invention relates to a processing method, including the calculation of one function between a datum to be compared and a reference datum. The function can be written in the form of a sum of: a term that depends on the datum to be compared, a term that depends on the reference datum, and a polynomial, such that all the monomials of the polynomial include at least one coordinate of each datum. The method includes an initialization step including: generating masking data; scrambling reference data by means of a server unit on the basis of said masking data; and calculating, by means of a client unit, the term of the function that depends on the datum to be compared.

Abstract: The invention presents a process for obtaining candidate reference data to compare to a data to be identified, implemented in a system comprising a client unit and a storage server comprising two databases, in which: —the first database comprises indexed memory blocks each comprising a corresponding encrypted indexed reference data, and—the second database comprises memory blocks indexed by all possible hash values obtained by a plurality of k indexed hash functions, and wherein each block contains a list of the indexes of the reference data which hashing by one of said hash function results in the hash value corresponding to said block, said process comprising the steps during which: —the client unit hashes the data to be identified with each of the plurality of hash functions, and reads the k memory blocks of the second database corresponding to the hash values thus obtained, the client unit identifies indexes contained in at least t out of k read memory blocks, and—the client unit reads the memory blocks o

Abstract: The invention relates to a method for signing a message (m), implemented by processing means of a user device of a member (Mi) belonging to a group of members (G), said user device having a secret signature key (ski), said method including a step of generating (E301) a group signature (?) for the message (m), enabling said member (Mi) to prove his membership in the group (G), and a step of generating (E302) a pseudonym (nymij) identifying the member (Mi) within a domain (Dj) of a service provider (SPj), said domain including a set of terminals in communication with a server of said service provider, said signature (?) being designed such that said member (Mi) can prove, by signing the message (m), his knowledge of said secret signature key without disclosing it, said group signature (?) being designed such that the membership of the member (Mi) in the group is verifiable independently from the pseudonym (nymij), said pseudonym and said signature being a function of a portion (xi) of said secret signature k

Abstract: The invention concerns a method for encrypting a binary data item characterised in that it comprises the steps consisting of: —generating a public key and a private key, the public key being a sparse matrix comprising m rows and n columns, m being greater than the number I of bits of the binary data item, I being an integer strictly greater than 1, and the private key being a set of I indexed sets of integers between 1 and m such that for each set, the sum of the elements of the rows of the sparse matrix indexed by the elements of a set is zero, and—generating a binary sequence b comprising m bits, such that b=Mx+e+y in which o x is a random binary vector, o e is a random binary noise vector, and o y is a linear encoding of data item c. The invention also concerns a method for calculating a Hamming distance on data encrypted by the method of encryption.

Abstract: The description relates in particular to a method of secure distributed storage, to a secure access method and to a distributed storage, and to devices, systems, computer programs and storage medium for the implementation of such methods.

Abstract: The invention relates to a secure method of processing data in which method is implemented the evaluation of a function that may be written as a linear combination of sub-functions with two binary inputs, in which a client and a server each possess a binary code, comprising n indexed bits, the method comprising the evaluation of the function with the binary codes of the client and of the server as inputs, without one of the client or the server obtaining information about the code of the other, the method being characterized in that it comprises the following steps: —the server randomly generates n indexed values and calculates the linear combination of these values with the same linear combination as that applied to the sub-functions to obtain the function, —the client implements, for each bit of his binary code, a technique of unconscious transfer to obtain from the server an intermediate data item comprising the randomly generated value of same index as the bit of the code of the client, increased by the v

Abstract: The invention is about an identification process of an individual or object, in a system comprising a control server and a management server of a database comprising N indexed data of N stored individuals, in which, to identify the individual or object, its datum is compared to each of the N data of the base.

Abstract: The invention relates to a method and system for managing and checking different identity data relating to a person. According to the invention, a derived-identity management server generates for the person at least part of the identity data with which said person can be authenticated in relation to a service provider for the derived-identity domain, on the basis of information derived from identity data from parent domains. The identity data generation processing ensures that no link can be established from two authentications in two separate domains in the absence of link information. If necessary, said link information is transmitted by a parent domain to a derived-identity server so that the latter establishes the link between the identity data of the derived-identity domain and the identity data of the parent domain, e.g. for the cascade revocation of a person from various domains.