强不可伪造的基于身份服务器辅助验证签名方案

标准模型下的基于身份签名方案大多数是存在性不可伪造的，无法阻止攻击者对已经签名过的消息重新伪造一个合法的签名，并且验证签名需要执行耗时的双线性对运算。为了克服已有基于身份签名方案的安全性依赖强和计算代价大等缺陷，提出了一个强不可伪造的基于身份服务器辅助验证签名方案，并在标准模型下证明了新方案在合谋攻击、自适应选择身份和消息攻击下是安全的。分析结果表明，新方案有效减少了双线性对的计算量，大大降低了签名验证算法的计算复杂度，在效率上优于已有的基于身份签名方案。

ID-based server-aided verification signature scheme with strong unforgeability

Most identity-based signature schemes in the standard model are existentially unforgeable,which cannot prevent adversaries from forging valid signatures on messages that have previously been signed.However,signature verification algorithms of ID-based signature schemes in the standard model require expensive bilinear pairing operations.In order to overcome the shortcomings of the existing ID-based signature schemes such as strong security assumption and high computation cost，a strongly unforgeable ID-based server-aided verification signature scheme was presented.This scheme was proven to be secure under collusion attacks,adaptive chosen identity and message attacks in the standard model.Analysis results show that the proposed scheme effectively reduces computation cost of pairing operation,and it greatly reduces computational complexity of signature verification algorithm.The proposed scheme is more efficient than the existing ID-based signature schemes.