Authentication token for identifying a cloning attack onto such authentication token

摘要

The invention relates to an authentication token for a communication network. The token may include a microprocessor, a memory, a stored secret key (Ki) and a set of instructions for controlling the microprocessor into performing an authentication calculation on the basis of a received random (RAND) and on the basis of the stored secret key. The token further includes a memory location dedicated for storing a counter value and it includes instructions for making the counter value evolve each time the authentication calculation is performed.