Patent ID: 7032109

Claim:
A method enabling the users ( 11 ) of a computer network, who have multimedia terminals ( 16 ) with a microphone ( 17 ) and are connected to the computer network, located at a distance from a service provider ( 12 ), to access securely and rapidly the services ( 30 ) that the service provider ( 12 ) offers to the users ( 11 ) of the computer network, said method comprising the following steps: the service provider ( 12 ) supplies to each of the users ( 11 ) of the computer network, who have subscribed to the services, a credit-card sized card ( 10 ), customized with specific identifiers for each subscriber and each card, said credit-card sized card ( 10 ) issues short ID audio signals ( 20 ), of DTMF type, encrypted at least partially, varying for each transaction, when it is activated ( 14 ) by the user ( 11 ) of a computer network, said card ( 10 ): further calculates ( 105 ) the number of times C(p,n) ( 242 ) that said card has been activated ( 14 ) and has issued said audio signals ( 20 ), wherein C(p,n) takes account of all activations, including activations at a wrong time, issues ID audio signals ( 20 ) representative of the number of times C(p,n) ( 242 ) that it has been activated, and encrypts ( 103 ) the ID audio signals ( 20 ) into a function S(p,n) as a function of said number of times C(p,n) ( 242 ) that said card has issued said audio signals ( 20 ) and as a function of said specific identifiers of the subscriber and the card, said ID audio signals ( 20 ) are received through the microphone ( 17 ) of the multimedia terminal ( 16 ) and transmitted via the computer network ( 15 ) to the computer facility ( 18 ) of the service provider, the signals transmitted to the computer facility ( 18 ) and the specific identifiers of the subscriber and the card, held ( 23 ) by the computer facility ( 18 ), are processed ( 24 ) and compared ( 25 ) electronically by the computer facility ( 18 ) of the service provider by computer means which: store ( 230 ) the number of times C(p,m) ( 246 ) the card has been used at a time of a last validation operation, compare ( 245 ) the number of times C(p,n) ( 242 ) the card has been activated, at the time of the current transaction, to the number of times stored C(p,m) ( 246 ), reject the current transaction if C(p,n) ( 242 ) is less than or equal to C(p,m) ( 246 ) and continue with the verification of the current transaction if C(p,n) ( 242 ) is greater than C(p,m) ( 246 ), recalculate the ID audio signals ( 20 ) into a function S′(p,n) as a function of said number of times C(p,n) ( 242 ) that said card has issued said audio signals ( 20 ) and as a function of said specific identifiers of the subscriber and the card, and then compare S′(p,n) to S(p,n), so that in case of a match, the subscriber ( 11 ) can immediately be put through to the services ( 30 ) of the service provider ( 12 ).