A threshold signature scheme for group communications without a shared distribution center

Abstract

In this paper, we shall propose a (t, n) threshold signature with (k, l) threshold-shared verification to be used in a group-oriented cryptosystem without a shared distribution center (SDC). In this scheme, any t participants can represent a group (signing group) to sign a message, and any k participants can represent another group (verifying group) to verify the signature. We need no SDC to distribute the public and private keys to all the participants in the two groups. Hence, our scheme is more practical in real-world applications and more efficient than its predecessors in terms of communication and computational complexity as well as storage. (C) 2003 Elsevier B.V. All rights reserved.