Abstract: This paper presents a security analysis of the certificateless signature scheme with revocation given by Ju et al., and shows that the identity revocation property of the scheme can be easily damaged. Based on this idea, using bilinear pairing, it proposes an improved certificateless signature scheme with identity revocation and gives its security proof under the oracle model. Due to the sound properties of bilinear pairing, the scheme is simple and efficient.

Key words: certificateless signature, key escrow, identity revocation, Security Mediator(SEM), bilinear pairing

摘要： 讨论密码方案中的身份撤销问题。对JKLLC签名方案进行了安全性分析，指出该方案实际上不具有身份撤销功能。对该方案加以改进，以双线性对为工具给出一种新的无证书签名方案并讨论其安全性。新方案不但增强了方案的身份撤销功能，而且在随机寓言模型下是可证明安全的。因为双线性对具有良好的性质，所以新方案简单、高效。

关键词: 无证书签名, 密钥托管, 身份撤销, 安全中介, 双线性对

CLC Number: 

• TP309