Abstract: A cryptographic method including: generating by a first device having a datum x an RSA module N; computing by the first device a number C=gbaxh1, g being an element of sub-group G of order bd, h1 being an element of sub-group H of order f, and a, b, d, f being integers, b and f being mutually prime, and x and y being less than d/a; sending C to a second device having datum y; computing by the second device D=Cu·bd?ay(gh3)vh2, u and v being random numbers and h2 and h3 being elements of H, and a first fingerprint (gh3)v; sending to the first device, D and the first fingerprint; computing by the first device (Df)f?, f?=1/f; obtaining based on (Df)f? a second fingerprint; and determining whether x is greater than or equal to y or x is less than y by comparing the first and the second fingerprints.

Abstract: A method for anonymous signature of a message executed by a member entity of a group. The method includes: registering the member entity with an administration entity of the group; generating by the member entity a trace from a trace generator calculated by at least one revocation entity and included in a public key of the group, the trace being invariant relative to the anonymous signatures generated by the member entity in accordance an anonymous signature scheme; blindly obtaining by the member entity a private group key; and generating at least one signature according to the anonymous signature scheme by using the private key, the signature comprising the trace.

Abstract: The method of the invention comprises: an identification step (E30-E50) of identifying the user of the mobile terminal; a generation step, triggered if identification is successful, of a secure element of the terminal generating (E70) at least one identification value for the terminal by using a first secret key shared between the secure element and a token service provider device; a sending step (E100) of sending a request to the token service provider device to obtain at least one security token, the request including said at least one identification value for the terminal; and a reception step (F90) of receiving from the token service provider device said at least one security token in encrypted form, each security token being associated with a random number generated by the token service provider device and being encrypted by means of an encryption key generated for that token from the random number and from a second secret key shared between the token service provider device and the secure element of th

Abstract: A method for anonymous signature of a message executed by a member entity of a group. The method includes: registering the member entity with an administration entity of the group; generating by the member entity a trace from a trace generator calculated by at least one revocation entity and included in a public key of the group, the trace being invariant relative to the anonymous signatures generated by the member entity in accordance an anonymous signature scheme; blindly obtaining by the member entity a private group key; and generating at least one signature according to the anonymous signature scheme by using the private key, the signature comprising the trace.

Abstract: A cryptographic method including: generating by a first device having a datum x an RSA module N; computing by the first device a number C=gbaxh1, g being an element of sub-group G of order bd, h1 being an element of sub-group H of order f, and a, b, d, f being integers, b and f being mutually prime, and x and y being less than d/a; sending C to a second device having datum y; computing by the second device D=Cu·bd?ay(gh3)vh2, u and v being random numbers and h2 and h3 being elements of H, and a first fingerprint (gh3)v; sending to the first device, D and the first fingerprint; computing by the first device (Df)f?, f?=1/f; obtaining based on (Df)f? a second fingerprint; and determining whether x is greater than or equal to y or x is less than y by comparing the first and the second fingerprints.

Abstract: A method for anonymously identifying a security module by a server. The method includes: receiving, from the module, a request for the address of a server managing subscription data of an operator, the request including a current identification value of the module, which depends on an identifier of the module and a current date; searching for the current identification value in at least one set of identification values, the set being associated with an operator and including, for a given module, a plurality of identification values, which are calculated depending on the identifier of the module and a date, the date varying for the plurality of identification values of the set between a start date and an end date; and sending, to the security module, the address of the server managing subscription data associated with the operator when the current identification value appears in the set of identification values.

Abstract: The method of the invention comprises: an identification step (E30-E50) of identifying the user of the mobile terminal; a generation step, triggered if identification is successful, of a secure element of the terminal generating (E70) at least one identification value for the terminal by using a first secret key shared between the secure element and a token service provider device; a sending step (E100) of sending a request to the token service provider device to obtain at least one security token, the request including said at least one identification value for the terminal; and a reception step (F90) of receiving from the token service provider device said at least one security token in encrypted form, each security token being associated with a random number generated by the token service provider device and being encrypted by means of an encryption key generated for that token from the random number and from a second secret key shared between the token service provider device and the secure element of th

Abstract: A method for anonymously identifying a security module by a server. The method includes: receiving, from the module, a request for the address of a server managing subscription data of an operator, the request including a current identification value of the module, which depends on an identifier of the module and a current date; searching for the current identification value in at least one set of identification values, the set being associated with an operator and including, for a given module, a plurality of identification values, which are calculated depending on the identifier of the module and a date, the date varying for the plurality of identification values of the set between a start date and an end date; and sending, to the security module, the address of the server managing subscription data associated with the operator when the current identification value appears in the set of identification values.

Abstract: A method for unique authentication of a user including federating an identity of said user for said service provider and an identity of the user for an identity provider, the federating including the steps of generating a user alias for that service provider and sending said identity provider a masked alias deduced from said alias, the identity provider associating said masked alias for that service provider with the identity of the user for the identity provider and sending the user elements for calculation by the user of a signature of a message containing the non-masked alias calculating said signature and sending the service provider said message with said signature, and the service provider verifying said signature, authenticating the user, and associating said alias with the user's identity.

Abstract: The invention relates to a method for generating a list signature for a message to be signed, said method comprising steps which are carried out by an electronic material support of a member of a list. During said step, the electronic material support only generates an electronic signature according to a sequence number supplied to the electronic material support by a certifying authority, according to evidence of belonging to the list of members, to data relating to the electronic material support, and optionally to a key of an authority qualified to lift the anonymity of the generated signature.

Abstract: The present invention relates to a method of access to a service consisting in i) identifying and registering a client (C), ii) authenticating the client to an anonymous certification authority, iii) authenticating the client by producing an anonymous signature and opening and maintaining an anonymous authentication session with a server (Se), and iv) selectively allowing contact between the server (Se) and the anonymous certification authority (ACA) to revoke the anonymity of the client (C) using the signature provided in step iii). The invention also relates to a system for opening and maintaining an authentication session guaranteeing non-repudiation.

Abstract: The invention relates to a method for unique authentication of a user (U) by at least one service provider (SP), said method including a preliminary identity federation stage of federating an identity (user@sp) of said user for said service provider and an identity (user@idp) of the user (U) for an identity provider (IdP).

Abstract: A method and system for electronic voting over a network, from a terminal (Te) connected to an administrative server (SA) and to a vote-counting server (SCV). An authentication certificate (CA) and a single-use password (UPWe) are calculated and transmitted (A) from the server (SA) to the voter (Eu), an electronic ballot paper (EB) and an anonymous reference (AREu) are transmitted (B) from the terminal (Te) to the server (SCV) and, upon verification (B1) of the anonymous reference, the vote and the paper are validated (B3), the paper is counted, a confirmation of receipt (ACW) and an electoral register document (DVR) are transmitted from the server (SCV) to the terminal (Te). The terminal (Te) signs the register and transmits (C) the signed register (SDVR) to the server (SA) which closes (D1) the vote of the voter (Eu).

Abstract: The invention concerns a system enabling a member (M) of a group (G) to produce, by means of customized data (z; K), a message (m) accompanied by a signature (8) proving to a verifier that the message originates from a member of the group (G). The invention is characterized in that the customized data is in the form of an electronic physical medium (26). Advantageously, the latter also incorporates: encrypting means (B3) for producing a customized cipher (C) from the customized data prior to the signature S of the message (m), means (B5) for producing a combination of a message m to be signed and the cipher (C) associated with said message, for example in the form of a concatenation of the message (m) with the cipher (C), and means (B6) for signing (Sig) the message (m) with the customized data (z; K) in the form of a cipher (C) associated with said message. Advantageously, the physical medium is a smart card (26) or the like.

Abstract: The invention concerns a list signature method comprising: an organization phase whereby reliable authority defines parameters for implementing an anonymous electronic signature; a phase which consists in registering persons on a list of authorized members to generate a list signature, during which each person calculates a private key, and the reliable authority delivers to each person a certificate for membership of the list; a phase which consists in defining a serial number; a phase wherein a member of the list generates by means of certificate a signature containing an element common to all the signatures issued by one single member with one single serial number; a phase which consists in verifying whether the signature has been generated by a member of the list and whether the serial number has been used to generate the signature.

Abstract: An anonymous and secure on-line payment system and method based on the partially blind signature cryptographic method with revocable anonymity. To this end, an Anonymity Server (SA) enables the Customer (C) to acquire on-line anonymous payment means on the basis of a protocol that does not enable the Anonymity Server to link the payment means to the Customer (C). The Payment Server (SdP) comprises means for opening an anonymous account using the anonymous payment means (50). A Customer (C) can make an on-line purchase from a Merchant Site (SM) without having to give a bank card number and remaining anonymous to the merchant and more generally to any entity present in the transaction or absent therefrom. However, this anonymity may be revoked by a trusted entity in the event of fraud on the Customer. Finally, a Customer can make payments when on the move.

Abstract: In a fair blind signature process, a user interacts with a signer in order to complete a 7-tuple (A,e,s,t,xu,x,m) such that Ae=a0a1xa2ma3xua4ta5s (mod n), where a0, a1, a2, a3, a4 and a5 and n are elements of the Signer's public key (PUBKs). During the signature-issuing phase the user (U) provides the signer (S) with a data element (a1x) encrypted according to a key (f) known to a trusted authority (TA), and this data element (a1x) is disclosed during transmission of the signed message. Similarly, the signed message is transmitted associated with second encrypted data comprising a second data element (a3xu) encrypted according to a key (f) known to the trusted authority (TA), and this second data element (a3xu) is disclosed to the Signer during the signature-issuing phase. Thus, the trusted authority (TA) can revoke the anonymity of the digital signature.

Abstract: A cryptographic method and apparatus for anonymously signing a message. Added to the anonymous signature is another signature which is calculated (operation 13) using a private key common to all the members of a group authorized to sign and unknown to all revoked members. The private key is updated (operations 8, 11) at group level on each revocation within the group and at member level only on anonymous signing of a message by the member.

Abstract: A cryptographic method and a chip card which is used to carry out the method. Before any calculation is performed by a computing means of the chip card, the chip card reads (2) an integral list, in a storage means of a second entity, of identifiers of first proprietary entities of a chip card. Such list is linked to each status assigned to each of the first entities by the second entity. Subsequently, the chip card compares (3) the identifier stored in a storage means of the chip card with the contents of the list, in order to authorize (5) or prohibit (4) any calculation by the computing means depending on the result of the comparison.

Abstract: An anonymous and secure on-line payment system and method based on the partially blind signature cryptographic method with revocable anonymity. To this end, an Anonymity Server (SA) enables the Customer (C) to acquire on-line anonymous payment means on the basis of a protocol that does not enable the Anonymity Server to link the payment means to the Customer (C). The Payment Server (SdP) comprises means for opening an anonymous account using the anonymous payment means (50). A Customer (C) can make an on-line purchase from a Merchant Site (SM) without having to give a bank card number and remaining anonymous to the merchant and more generally to any entity present in the transaction or absent therefrom. However, this anonymity may be revoked by a trusted entity in the event of fraud on the Customer. Finally, a Customer can make payments when on the move.