METHOD AND SYSTEM FOR ENSURING THE SECURITY OF THE SUPPLY OF SERVICES OF TELECOMMUNICATION OPERATORS

The invention concerns a method and a system enabling a telecommunication operator (12) to identify rapidly and to debit in complete security the accounts of subscribers of a telephone network. The method comprises the following steps: the telecommunication operator (12) provides each of its subscribers (11) with a subscriber card (10), formatted like a credit card, personalised by specific identifiers for each subscriber and for each subscriber card; said card (10), formatted like a credit card, personalised by specific identifiers for each subscriber and for each subscriber card; said card (10), formatted like a credit card, emits brief identifying sound signals, of the DTMF type, at least partly encrypted, varying with each operation, when it is actuated (14) by the customer (11); the sound signals are received by the microphone (17) of the handset (16) and are converted into electric signals, before being transmitted by the communication network (15) to the computer service (18) of the telecommunication operator (12); the transmitted signals are electronically processed and decrypted (24) by the computer service (18) of the telecommunication operator (12) and the data obtained after processing are compared (25) to the identification data of the subscriber and the subscriber card in the possession of the computer service (18) of the telecommunication operator.