Secret-key and identification rates for biometric identification systems with protected templates

In this paper we consider secret generation in biometric identification systems with protected templates. This problem is closely related to the study of the bio metric identification capacity [Willems et al., 2003] and [O’Sullivan and Sclmmid, 2002] and the common randomness generation scheme [Ahlswede and Csiszár. 1993]. In our system two terminals observe biometric enrollment and identifi cation sequences of a number of individuals. It is the goal of these terminals to form a common secret for the sequences that belong to the same individual by interchanging public (helper) messages for all individuals in such a way that the information leakage about the secrets from these helper messages is negli gible. Moreover, based on the helper data produced by the first terminal, the second terminal has to establish tIme identity of the individual who presented his biometric sequence