A Threshold Ring Signature Scheme with a Variety of Keys

In this paper we present a (t, n)-ring signature scheme in which each ring member can use a different underlying signature scheme. The scheme is existentially secure in the random oracle model against adaptive chosenmessage attacks in which an adversary may corrupt up to t−1 ring members, under the security assumptions of the underlying signature schemes for each ring member. The threshold signature scheme presented is a generalization of the RSA-based threshold signature scheme by Bresson, Stern, and Szydlo from CRYPTO ’02 using a modification of the ring signature scheme of Abe, Ohkubo, and Suzuki from ASIACRYPT 2002.