Patent ID: 8190127

Claim:
A method for a first communications device to authenticate a second communications device, the method comprising: providing a first communications device with functional access to a challenge-response means which provides responses to challenges dependent upon a key held by the challenge-response means; at the first communications device, sending a challenge to the challenge-response means and receiving a corresponding response from the challenge-response means to establish a matched challenge-response pair; at the first communications device, storing the matched challenge-response pair in a memory; removing functional access to the challenge-response means from the first communications device; after said removal, providing a second communications device with functional access to the challenge-response means; at the first communications device, sending the challenge of the stored challenge-response pair to the second communications device; at the second communications device, sending the challenge of the stored challenge-response pair received from the first communications device to the challenge-response means and receiving at the second communications device a corresponding response from the challenge-response means; at the second communications device, sending the received response from the challenge-response means to the first communications device; and authenticating the second communications device at the first communications device by verifying that the response received from the second communications device is the same as the stored response.