关键词: 数字签名, 离散对数, 代理盲签名, 伪造攻击, 非关联性

Abstract: The proxy blind signature scheme based on DLP proposed by Tan et al. was analyzed, and it was found that this scheme does not possess the unforgeability. The original signer and the receiver could both forge a valid proxy blind signature for any message. At the same time, the proxy signer could make a linkage between a message signature and the corresponding blind message signature, which was called linkability. So an improved proxy blind signature scheme was proposed in this paper, which can not only resolved the security problems existing in the original scheme, but also has high efficiency.

Key words: digital signature, Discrete Logarithm Problem(DLP), proxy blind signature, forgery attack, unlinkability