We present a new identification scheme which is based on Legendre symbols modulo a certain hidden prime and which is naturally suited for low power, low memory applications. 1 Overview One of the most desirable cryptographic functions is a secure, small, zero-knowledge public-key identification scheme. The applications are many and obvious – even the single application of credit/smartcard security is enough to stimulate research. In this paper, we present a scheme that requires extremely little computing power to perform a verification and to which we refer as FLIP (Fast Legendre Identification Protocol). Our scheme is unbalanced by design: the party proving his/her identity needs almost no computing power, while the party to whom the identity is being proved needs only a very small amount. Our scheme is based on the assumption that integer factorization is a “hard problem.” In fact, we believe that the only feasible attack on our scheme is via the factorization of a certain ...
William D. Banks, Daniel Lieman, Igor Shparlinski