Analysis and Improvement of a Threshold Signature Scheme Based on the General Access Structure

AbstractHua-wang Qin et al. proposed a novel threshold signature scheme based on the general access structure in order to break the applied limitation of the conventional threshold signature schemes. The security of the scheme was analyzed in this paper, and it is pointed out that the scheme is insecure because it cannot withstand conspiracy attacks and what's more, the identity of signer cannot be investigated. To overcome these security vulnerabilities, this paper proposed an improved threshold signature scheme, and the security analysis results show that the improved scheme can not only resist the conspiracy attack, but also have the properties of anonymity and traceability simultaneously

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

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