对成林等人提出的基于离散对数的部分盲签名方案进行了安全性分析,指出方案不能抵抗篡改协商信息攻击,即恶意的签名请求者可以非法修改事先协商的公共信息.为此,提出了一种改进的部分盲签名方案.安全分析结果表明,改进方案能够有效防止恶意请求者篡改公共信息,保护了签名者的合法权益. This paper analyzes the security of partial blind signature scheme based on discrete logarithm proposed by Cheng Lin et al. And points out that the scheme can not resist tampering with the negotiation information attack, that is, the malicious signer can illegally modify the public information negotiated in advance. An improved partially blind signature scheme is proposed.The security analysis results show that the improved scheme can effectively prevent malicious requesters from tampering with public information and protecting the legitimate rights and interests of signers.