摘要： 分析一种基于身份的代理签名方案(哈尔滨工业大学学报，2008年第7期)，指出其不安全性，容易受到PKG发起的假冒伪造攻击，PKG可以假冒原始签名人代理授权，也可以伪造有效的代理签名。给出改进方案，以纠正原方案的错误，可有效弥补原方案的设计缺陷，限制PKG的权限，保护签名人的利益。

关键词: 信息安全, 数字签名, 代理签名, 基于身份, 双线性对

Abstract: Through the security analysis of an ID-based proxy signature scheme (Journal of Harbin Institute of Technology, 2008, No2), this paper points out it is unsafe and suffers from forgery attack launched by PKG. PKG not only can counterfeite proxy-authorization, but also can forgery a valid proxy signature. An improved scheme based on the property of original scheme is proposed and its security weakness is overcome. In the new scheme, the power of PKG is limited and the benefit of signer is protected, so it is more secure and efficient.

Key words: information security, digital signature, proxy signature, ID-based, bilinear pairings

中图分类号: 

• TP309