Abstract: To improve the computational efficiency, this paper proposes an efficient provably secure certificateless proxy signature scheme based on elliptic curve discrete logarithm problem, avoiding bilinear pairing. The proposed scheme is more computationally efficient than the existing schemes. Its generate-partial-proxy-key algorithm needs one scalar multiplication, its validate-partial-proxy-key algorithm needs two scalar multiplications, and its signing algorithm only needs one scalar multiplication, its validation algorithm only needs six scalar multiplications. Furthermore, its signature length is shorter. The proposed scheme is existentially unforgeable in adaptive chosen message and iden-  tity for super adversary, and is particularly suitable for practical applications with limited bandwidth and power- constrained devices.

Key words: certificateless public key cryptography, proxy signature, elliptic curve discrete logarithm problem, random oracle model

摘要： 为提高无证书代理签名方案的计算效率，提出了一个高效的无证书代理签名方案。该方案的安全性基于椭圆曲线离散对数难题，不使用双线性对，其效率比现有的无证书代理签名方案有很大提高。在部分代理钥生成阶段只需1个标量乘，在部分代理钥验证阶段只需2个标量乘，在代理签名阶段只需1个标量乘，在代理签名验证阶段只需6个标量乘，且签名长度较短。所提方案对于超级攻击者在适应性选择消息与身份下是存在性不可伪造的，适用于对计算和存储等资源有严格限制的实际应用场合。

关键词: 无证书密码体制, 代理签名, 椭圆曲线离散对数难题, 随机预言机模型