Journal of Applied Science and Engineering

Published by Tamkang University Press


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Shin-Jia Hwang This email address is being protected from spambots. You need JavaScript enabled to view it.1 and Hao-Chih Liao1

1Department of Computer Science and Information Engineering, Tamkang University, Tamsui, Taiwan 251, R.O.C.


Received: March 28, 2005
Accepted: June 6, 2005
Publication Date: March 1, 2006

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Lee and Hwang proposed group-oriented undeniable signature schemes with a trusted center to guard against Langford’s attack. Unfortunately, there are some security weaknesses in Lee-Hwang’s schemes. Their schemes assume that the signers and verifier should honestly perform steps; otherwise their schemes will fail. To remove this impractical assumption and the corresponding problems, our improvement is proposed.

Keywords: Undeniable Signatures, Group-Oriented Signatures, Threshold Signatures, Digital Signatures


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