Abstract: A method of securing a telecommunication terminal that is connected to a module used to identify a user of the terminal is described. The method includes a step including executing a procedure in which the terminal is matched to the identification module, consisting in: securely loading a first software program including a data matching key onto the identification module; securely loading a second software program which can operate in conjunction with the first software program onto the telecommunication terminal; transmitting a data matching key that corresponds to that of the first software program to the second software program; storing the transmitted data matching key in the secured storage zone of the telecommunication terminal; and conditionally submitting every response from the first software program to a request from the second software program upon verification at the true value of the valid possession of the data matching key by the second program.

Abstract: The invention relates to multipurpose electronic payment method and system. The inventive method consists in transmitting (A) from a multimedia terminal (TM) a payment order (MP) issued from at least one multimedia application hosted in the (TM) to a local proxy for payment (PP), in discriminating (B) said payment order in (PP) upon a specific local processing criterion respectively remote, in carrying out (C) a local payment upon the retained local payment specific criterion, if not in transmitting (D) the payment order to a remote system (SD) for carrying out a remote payment. Said invention is usable for proximity payment transitions, external payment or for electronically carrying out a telepayment.

Abstract: Method of cryptography in a smart card comprising a central processing unit, said method implementing precomputation operations, characterized in that said precomputation operations are performed by the smart card and in that the precomputation operations are carried out at a session during the waiting periods of the inputs/outputs of the central processing unit.

Abstract: The cryptographic method is used in transactions for which a first entity generates, by use of a private RSA key, a proof verifiable by a second entity by use of a public RSA key associated with said private key. The public key includes an exponent and a modulus. The first entity generates a first element of proof by a calculation that can be performed independently of the transaction, and a second element of proof related to the first element of proof and which depends on a common number shared by the first and the second entities specifically for the transaction. The second entity verifies that the first element of proof is related, modulo the modulus of the public key, to a power of a generic number, with an exponent equal to a linear combination of the common number and of a product of the exponent of the public key by the second element of proof.

Abstract: To check a digital signature, using a microcircuit card, the microcircuit being designed to receive and to process requests to check digital signatures, the process comprises storing in a memory in the microcircuit a certificates table containing digest forms of authorized public keys, and a phase of checking a digital signature consisting of: receiving by the microcircuit the digital signature to be checked and a public key corresponding to a private key that was used to generate the digital signature to be checked; calculating a digest form of the received public key, searching for the calculated digest form of the public key in the certificates table, and decrypting the digital signature using the received public key if the calculated digest form of the public key is located in the certificates table.

Abstract: After a preliminary exchange between the vendor and the purchaser with a view to completing a transaction corresponding to the payment of an amount due to the vendor for a service rendered, information is exchanged only between the purchaser and a telepayment server (T). The purchaser sends the telepayment server information (1) including data relating to the vendor and said amount. The server then authenticates the vendor's identifier (I1) on the basis of the information received and responds by sending the purchaser a message (2) instructing payment of said amount and including at least said amount and the identifier (I1) of the vendor. The purchaser responds by sending the server confidential information (3) enabling payment of said amount, after verification by the purchaser of the identifier (I1) of the vendor.

Abstract: The present invention relates to a cryptographic method of protecting an electronic chip against fraud and a device including an electronic chip which is adapted to protect the electronic chip against fraud. The method includes: mixing some or all of the input parameters (Em) to supply an output data item E?=(e?1, e?2, . . . , e?n, . . . , e?N), changing the state of a finite state automaton from an old state to a new state as a function of the data item E?=(e?1, e?2, . . . , e?n, . . . , e?N), and calculating a certificate (S) by means of an output function having at least one state of the automaton as an input argument. The device includes: mixing means, a finite state automaton, and output means for calculating a certificate (S).

Abstract: The invention relates to multipurpose electronic payment method and system. The inventive method consists in transmitting (A) from a multimedia terminal (TM) a payment order (MP) issued from at least one multimedia application hosted in the (TM) to a local proxy for payment (PP), in discriminating (B) said payment order in (PP) upon a specific local processing criterion respectively remote, in carrying out (C) a local payment upon the retained local payment specific criterion, if not in transmitting (D) the payment order to a remote system (SD) for carrying out a remote payment. Said invention is usable for proximity payment transitions, external payment or for electronically carrying out a telepayment.

Abstract: A method of securing a telecommunication terminal that is connected to a module used to identify a user of the terminal is described. The method includes a step including executing a procedure in which the terminal is matched to the identification module, consisting in: securely loading a first software program including a data matching key onto the identification module; securely loading a second software program which can operate in conjunction with the first software program onto the telecommunication terminal; transmitting a data matching key that corresponds to that of the first software program to the second software program; storing the transmitted data matching key in the secured storage zone of the telecommunication terminal; and conditionally submitting every response from the first software program to a request from the second software program upon verification at the true value of the valid possession of the data matching key by the second program.

Abstract: Authentication and signature process with reduced number of calculations. The process involves a first entity called the “prover”, which possesses a public key v and a secret key s, these keys verify the relation v=s?t (mod n), where n is an integer called modulus and t is a parameter, and a second entity called a “verifier”, which knows the public key v. This process implies exchange of information following a “zero-knowledge protocol” between the verifier and the prover and cryptographic calculations on this information, some calculations being carried out “modulo n”. The process of the invention is characterised by the fact that the modulus n is specific to the prover that communicates this modulus to the verifier.

Abstract: To check a digital signature, using a microcircuit card, the microcircuit being designed to receive and to process requests to check digital signatures, the process comprises storing in a memory in the microcircuit a certificates table containing digest forms of authorized public keys, and a phase of checking a digital signature consisting of: receiving by the microcircuit the digital signature to be checked and a public key corresponding to a private key that was used to generate the digital signature to be checked; calculating a digest form of the received public key, searching for the calculated digest form of the public key in the certificates table, and decrypting the digital signature using the received public key if the calculated digest form of the public key is located in the certificates table.

Abstract: The cryptographic method is used in transactions for which a first entity generates, by means of a private RSA key, a proof verifiable by a second entity by means of a public RSA key associated with said private key. The public key includes an exponent and a module. The first entity generates a first element of proof by a calculation that can be performed independently of the transaction, and a second element of proof related to the first element of proof and which depends on a common number shared by the first and the second entities specifically for the transaction. The second entity verifies that the first element of proof is related, modulo the module of the public key, to a power of a generic number, with an exponent equal to a linear combination of the common number and of a product of the exponent of the public key by the second element of proof.

Abstract: A method for making a telecommunication terminal secure when it is connected to a terminal user identification module. The method including execution of a matching procedure in which the terminal transmits terminal identification information to the identification module connected to the terminal, and the identification module compares the identification information received from the terminal with terminal identification information stored in a memory, transmits the result of the comparison to the terminal, and if the identification information stored by the identification module corresponds to the information for the terminal, it sets an internal matching indicator (LOCK) indicating that the terminal has been identified by the identification module.

Abstract: Electronic payment process and system for implementing such a process. Customer equipment is mobile equipment, for example of the GSM type. In addition to the customer (C) and the merchant (M), a gateway (P) participates in the transaction, authenticates the customer and the merchant and ensures that the goods item ordered will be duly paid for. Customer equipment may work with a bank payment card.

Abstract: The present invention relates to a cryptographic method of protecting an electronic chip against fraud and a device including an electronic chip which is adapted to protect the electronic chip against fraud.

Abstract: After a preliminary exchange between the vendor and the purchaser with a view to completing a transaction corresponding to the payment of an amount due to the vendor for a service rendered, information is exchanged only between the purchaser and a telepayment server (T). The purchaser sends the telepayment server information (1) including data relating to the vendor and said amount. The server then authenticates the vendor's identifier (I1) on the basis of the information received and responds by sending the purchaser a message (2) instructing payment of said amount and including at least said amount and the identifier (I1) of the vendor. The purchaser responds by sending the server confidential information (3) enabling payment of said amount, after verification by the purchaser of the identifier (I1) of the vendor.

Abstract: The invention proposes, firstly, a method of managing a proof of the reservation by a customer (C) of a product or a service, the method consisting in a reservation management unit (RMU) sending (300) a portable object (MP) of the customer (C) reservation data which is stored in a memory of the portable object (MP) to serve as proof of the reservation, and, secondly, a system for implementing the method.

Abstract: Method of cryptography in a smart card comprising a central processing unit, said method implementing precomputation operations, characterized in that said precomputation operations are performed by the smart card and in that the precomputation operations are carried out at a session during the waiting periods of the inputs/outputs of the central processing unit.

Abstract: A method for performing electronic transactions between a card, a service provider having at least one terminal configured to accept the card and a centralized system configured to be connected to the terminal. The terminal transmits to the card a parameter M including the sum of the transaction and its identity. The card produces two signatures, a first signature (z) depending on a secret debit key (k) and on the parameter (M), this first signature being a proof that the card balance has been debited; and a second signature (y) depending on the first signature (z), the second signature being produced either by an RSA algorithm or by an interactive algorithm. The terminal checks the second signature (y) but not the first one because it is unable to recover the secret debit key (k). The terminal stores the different first signatures (proofs) (z) and the parameters (M) for the different transactions. The centralized system can collect the first signatures and the parameters.

Abstract: Authentication and signature process with reduced number of calculations. The process involves a first entity called the “prover”, which possesses a public key v and a secret key s, these keys verify the relation v=s?t (mod n), where n is an integer called modulus and t is a parameter, and a second entity called a “verifier”, which knows the public key v. This process implies exchange of information following a “zero-knowledge protocol” between the verifier and the prover and cryptographic calculations on this information, some calculations being carried out “modulo n”. The process of the invention is characterised by the fact that the modulus n is specific to the prover that communicates this modulus to the verifier.