Patent ID: 7660772

Claim:
A method, comprising: generating with a computer a set of subscriber-specific authentication data blocks into a network, each data block containing a challenge, a response and a key, where the generation is performed in the same manner as in a known mobile communications system; transmitting with a transmitter at least some of the challenges contained in the authentication data blocks to a terminal; choosing one of the challenges for use in the terminal, and based on the challenge, determining a response and a key to be used with an aid of an identification device of the terminal essentially in the same way as in a subscriber identification module of the mobile communication system; determining an authenticator with an aid of the chosen key in the terminal; transmitting, from the terminal to the network, the authenticator and data, the data containing information relating to the manner in which the authentication is formed and notifying the network with the aid of the data of which key corresponding to which challenge was chosen, and a check value with the aid of the chosen key in the network; and comparing the check value with the authenticator.