Method and apparatus for authenticating users of a subscriber line

摘要

A subscriber is identified, the subscriber being connected to an exchange via a main distributor using a so-called intelligent subscriber connection. A secret subscriber code is stored on a chip card, as is a cryptographic authentication algorithm. A test number is provided for each subscriber authentication in the authentication procedure. The test number and/or the authentication message are transmitted in the form of phase shift keying (PSK) signals. The authentication message is compared with the message calculated from the authentication algorithm. The secret subscriber code may be stored at the exchange.