中文摘要：

近年来,环签名以其广泛的应用受到人们的普遍关注.然而,大部分的基于身份环签名都是利用双线性对构造的.本文分析了熊虎等利用二次剩余构造的基于身份的环签名方案,指出该方案的签名和验证算法在计算上是不可行的.针对这个问题,给出了改进方案.分析表明,改进方案解决了原方案的计算问题,并且按照原方案的证明方法,在随机预言模型下,改进方案仍然是适应性选择消息和身份攻击下存在性不可伪造的,并满足签名者无条件匿名性.

英文摘要：

Ring signature is very attractive for its wide application.However,most of the existing ID-based ring signatures are constructed from bilinear pairings.This paper analyzed the identity-based ring signature scheme based on quadratic residues proposed by Xiong et al,and proved that the algorithm of signature and verification of the scheme is not feasible in computation.In order to solve these problems,the original scheme was improved.The improved schemes can be proved to be existentially unforgeable against adaptive chosen massage and identity attack under the random oracle model and anonymous in the method of original scheme.