Patent ID: 7249108
Filing Date: 2007-07-24
Classification: B41J,G06Q,G09C,H04L,H04N

Abstract:
1. A validation protocol performed in a system for determining whether an untrusted authentication chip in communication with the system is valid, or not, including the steps of: generating a random number in a trusted authentication chip in communication with the system; applying, in the trusted authentication chip, a keyed one way function to the random number using a first secret key from the trusted authentication chip to produce a first encrypted outcome; applying, in the untrusted authentication chip, a keyed one way function to the random number using a second secret key from the untrusted authentication chip to produce a second encrypted outcome; comparing, using the system, the first encrypted outcome and the second encrypted outcome, without knowledge of the first and second secret keys, and in the event of a match considering the untrusted chip to be valid; otherwise considering the untrusted chip to be invalid.