摘要： 基于ElGamal签名体制，提出一个具有特定合成者的门限代理签名方案。当参与者加入或退出代理签名时，其他各参与者的子代理密钥无需更新，而且在签名参与者间不需要维护一条安全信道，指定的签名合成者可根据签名参与者发送的信息验证各部分签名并合成签名。分析结果表明，在离散对数困难性问题下，该方案是安全的，且与基于ElGamal签名体制的门限代理签名方案相比，在代理签名的生成与验证阶段计算量和通信量较小，具有较高的安全性和效率。

关键词: 门限代理, ElGamal签名, 离散对数, 安全性, 代理密钥, 伪造攻击

Abstract: A scheme called threshold proxy signature with a specified signature folder is proposed based on ElGamal signature. In this scheme, when the participants are joining or quitting, the sub-key of participants do not require to be update and the system do not need to maintain a secure channel between the signature participants to specify the signature. After finishing the part signature, the signature folder verifies them and combine it. The security of the scheme is ensured by the difficulty of solving discrete logarithm. Compared with scheme proposed by threshold proxy signature scheme of ElGamal signature scheme, it has smaller quantity of computation and communication during the proxy signature stage. So it is more safe and more efficient.

Key words: threshold proxy, ElGamal signature, discrete logarithm, security, proxy key, forgery attack

中图分类号: 

• TP309