“Untraceability†Analysis of Proxy Blind Signature from Bilinear Pairings

Abstract

“untraceability†is an important property of Proxy blind signature from bilinear pairings. In order to enhance the security of Nong et al.’s schemes, Zhang presented some new untraceable blind signatures. However, this paper indicates there are three important conclusions:1. We prove that the cryptanalysis method proposed by Zhang is not proper and Nong et al’s scheme satisfies untraceability; 2. We proposes a new analysis method of untraceability which has proved that Nong et al.’s scheme is untraceable. Moreover, the method can also analyze other blind signature schemes 3.The efficiency of Nong et al.’s scheme is higher than the improved scheme of Zhang.