Method for securing a transaction performed by bank card

1. A method for securing a transaction made by bank card, the transaction involving a remote provision, by a user, of data existing in a bank card in the user's possession, the method comprising:

obtaining data existing in the bank card to be used, called textual data;

obtaining at least one portion of the textual data in the form of an audio data stream, called a sound sample, resulting from reading the data existing in the bank card to be used;

computing a current voice signature from said sound sample;

obtaining a telephone number, used for the remote providing of the textual data, called a current telephone number;

comparing said current voice signature with a reference voice signature pre-recorded and associated with the textual data of the bank card;

when the reference voice signature differs from the current voice signature by a value greater than a first value defined by a predetermined parameter, rejecting the transaction; and

when the reference voice signature differs from the current voice signature by a value greater than a second value defined by the predetermined parameter:

comparing the current telephone number with at least one reference telephone number pre-recorded and associated with said textual data of the bank card; and

when the current telephone number is not identical to one of the at least one reference telephone number, rejecting the transaction.

2. The method according to claim 1 , wherein said obtaining said sound sample is implemented concomitantly with obtaining said textual data when said textual data is communicated by telephone.

3. The method according to claim 1 , wherein obtaining said sound sample and computing said current voice signature are implemented by a communications terminal in the possession of said user.

4. The method according to claim 3 , wherein the method comprises:

receiving, by the communications terminal, a request for transmission coming from a transaction management server;

displaying, by the communications terminal a request for entering a personal identification code;

receiving an entry, by the user, of the personal identification code, and

when the personal identification code is correct, transmission of the current voice signature to the management server.

5. A server for controlling a validity of a transaction involving a remote providing, by a user, of data appearing in a bank card, wherein the server comprises:

means for obtaining data existing in the bank card to be used, called textual data;

means for obtaining at least one portion of the textual data, in the form of a stream of audio data, called a sound sample, resulting from a reading of the data existing in the bank card to be used;

means for computing a current voice signature from said sound sample;

means for obtaining a telephone number, used for the remote providing of the textual data, called a current telephone number;

means for comparing said current voice signature with a reference voice signature pre-recorded and associated with said textual data of the bank card;

means for rejecting the transaction when the reference voice signature differs from the current voice signature by a value greater than a first value defined by a predetermined parameter;

means for performing the following acts when the reference voice signature differs from the current voice signature by a value greater than a second value defined by the predetermined parameter:

comparing the current telephone number with at least one reference telephone number pre-recorded and associated with said textual data of the bank card; and

rejecting the transaction when the current telephone number is not identical to one of the at least one reference telephone number.

6. A non-transmissible computer-readable medium comprising a computer program product, which comprises program code instructions to execute a method for securing a transaction made by bank card, when the instructions are executed by a processor, wherein the transaction involves a remote provision, by a user, of data existing in a bank card in the user's possession, the method comprising:

obtaining data existing in the bank card to be used, called textual data;

obtaining at least one portion of the textual data in the form of an audio data stream, called a sound sample, resulting from reading the data existing in the bank card to be used;

computing a current voice signature from said sound sample;

obtaining a telephone number, used for the remote providing of the textual data, called a current telephone number;

comparing said current voice signature with a reference voice signature pre-recorded and associated with the textual data of the bank card;

when the reference voice signature differs from the current voice signature by a value greater than a first value defined by a predetermined parameter, rejecting the transaction; and

when the reference voice signature differs from the current voice signature by a value greater than a second value defined by the predetermined parameter:

comparing the current telephone number with at least one reference telephone number pre-recorded and associated with said textual data of the bank card; and

when the current telephone number is not identical to one of the at least one reference telephone number, rejecting the transaction.