Abstract: The identity-based multi-proxy signature schemes employing computation-intensive bilinear pairing operations have higher cost of computing. Based on the elliptic curve group, a pairing-free identity-based multi-proxy signature scheme is proposed. In the new scheme, user’s private key generation algorithm, delegation generation algorithm and multi-proxy signature generation algorithm are all derived from Schnorr’s short signature scheme. In the random oracle model, the new scheme achieves provable security, and its unforgeability is deduced to a polynomial time adversary solving the discrete logarithm problem. Comparative analysis shows that the new scheme is more efficient in computation.

Key words: identity-based cryptography, multi-proxy signature, discrete logarithm problem, random oracle model

摘要： 现有基于身份的多代理签名方案采用计算量大的双线性对运算，总体计算开销较高。基于椭圆曲线上的加法循环群，提出一种不使用对运算的基于身份多代理签名方案，其中，用户私钥产生、代理签名授权和多代理签名算法均来源于Schnorr的短签名机制。在随机预言模型下，新方案的不可伪造性被规约为多项式时间敌手求解离散对数问题，具有可证明安全性。对比分析表明，新方案计算开销更低。

关键词: 基于身份密码学, 多代理签名, 离散对数问题, 随机预言模型