Process and device for authenticating subscribers to digital exchanges

A method for authenticating subscribers to at least one exchange of a digital communication network, the digital communication network including at least one subscriber-side network terminator for connecting at least one data terminal, at least one authentication module arranged at a subscriber for receiving a first identification carrier containing a subscriber-specific cryptographic key, and at least one second authentication module arranged at one of the exchange and a location immediately upstream from the exchange for receiving a second identification carrier containing the subscriber-specific cryptographic key, the method comprising the steps of:

• transmitting information from the second authentication module to the first authentication module,
• encoding the information received with the subscriber-specific cryptographic key in the first authentication module, and transmitting the encoded information back to the second authentication module, and
• decoding the encoded information in the second authentication module with the subscriber-specific cryptographic key to authenticate the subscriber to the exchange.

A device for authentication of subscribers to at least one exchange of a digital communication network with at least one subscriber-side network terminator for connecting at least one data terminal, the device comprising:

• at least one first authentication module for receiving a first identification carrier, the first authentication module arranged at each subscriber;
• and
• at least one second authentication module for receiving a second identification carrier being arranged one of at and immediately upstream from the exchange, with the first and second authentication modules capable of at least one of encoding and decoding with a subscriber-specific key and of exchanging information for at least one of unilateral and bilateral authentication.