A remark on a non-interactive public-key distribution system

Abstract

An identity-based non-interactive public key distribution system was presented by these authors at Eurocrypt’ 91 [2]. It is based on the observation that for an appropriate choice of m, computing discrete logarithms in Zm* is feasible if and only if the factorization of m is known. This observation allows one to set up an exponential key distribution system in which a user’s (say Alice’s) public key is equal to her identity IA. A trusted authority who knows the factorization of m is required for computing (during registration) Alice’s secret key SA as the discrete logarithm of IA to some base g, where g is an element of Zm* with maximal order.