| CPC G06F 21/44 (2013.01) [G06F 12/1458 (2013.01); G06F 2212/1052 (2013.01)] | 20 Claims |

|
1. A method comprising:
providing, from a verifier module to an authenticator module, a block of data generated within the verifier module, a size of the block being correlated with one or more desired characteristics of the authenticator module, wherein the verifier module is a part of a host device, and the authenticator module is a part of an external add-on device to be connected with the host device;
providing, from the verifier module to the authenticator module, a challenge value;
receiving, at the verifier module, a response from the authenticator module, the response comprising a result derived from a calculation involving at least the challenge value and the block of data; and
verifying, at the verifier module, whether the response is indicative of the one or more desired characteristics of the authenticator module.
|