一种基于椭圆曲线的门限代理签名方案

在(t,n)门限代理签名方案中,原始签名人可将签名权授权给成员数为n的代理群,代理群中任何不少于t个代理签名人可代表原始签名人生成有效的签名.门限代理签名的特点使之具有广泛的实用性.目前所提出的门限代理签名方案多基于有限域上的离散对数问题.由于椭圆曲线密码体制在相同安全级别下,具有密钥短、速度快的优点,为此提出了一种基于椭圆曲线的不可否认门限代理签名方案,其安全性基于椭圆曲线离散对数问题难解性,同时可以在需要时实现对签名者的追查.安全性分析表明,该方案可有效地挫败合谋攻击和伪造攻击.同时由于椭圆曲线密码体制的特点,使该方案的计算量和通讯量都较小.

A threshold proxy signature scheme based on elliptic curve cryptosystem

In a(t,n) threshold proxy signature scheme,any t or more proxy signers from the delegated proxy group are allowed to delegate the original signer to generate a valid proxy signature.It is more feasible in the situation of practical application because some situations of group-oriented application are considered.By far,most threshold proxy signature schemes proposed are based on the discrete logarithm problem.Since elliptic curve cryptosystem has the advantages of shorter key and more rapid speed at the same security level,a threshold proxy signature scheme based on elliptic curves is presented.Its security is based on the elliptic curve discrete logarithm problem.And the actual signers can be identified if it is necessary.Through security analysis the proposed scheme is proved to be capable of withstanding conspiracy attack and forgery attack.Because of the property of the elliptic curve cryptography,this scheme is efficient in terms of computational complexity and communication cost.