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The Journal of China Universities of Posts and Telecommunications

December 2010, 17(6): 89–94 www.sciencedirect.com/science/journal/10058885 http://www.jcupt.com

New concurrent digital signature scheme based on the computational Diffie-Hellman problem

QIN Wen, ZHOU Nan-run ( )

Department of Electronic Information Engineering, Nanchang University, Nanchang 330031, China

Abstract

Based on strong designated verifiers signatures, a new fair concurrent signature scheme is proposed. Compared with the previous concurrent signature schemes, even if a keystone must be chosen by the initial signer, the matching signer will easily get the keystone through an extraction algorithm. Due to the property of strong designate verifying, the initial signer couldn’t make use of the keystone prepared carefully to deceive the matching signer. Then the matching signer is able to participate actively the signature scheme. Besides, there aren’t bilinear operations in the keystone algorithm to deliver the keystone efficiently. Therefore the efficiency of our signature scheme is also improved.

Keywords designated verifiers signature, fairness, concurrent signature, information security

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Introduction

Due to the rapid growth of electronic commerce nowadays, the fair exchange of the digital signatures has been proven to be an important and fundamental problem. If a signature is a fair exchange, the two entities can receive each other’s signature, or they cannot. In recent years, various schemes on the fair exchange problem have been proposed [1–6]. One kind of approaches to solving this fair exchange problem involves a trusted (or semi-trusted) third party or an arbitrator, who can be called upon to handle disputes between signers [1–3]. The main problem of this kind of approaches is the demand of a dispute-resolving third party with functions beyond those demands of a normal certification authority, since the appropriate third party may not be available. Another kind of...