中文摘要：

基于双线性对的无证书密码系统去除了公钥基础设施（PKI）中复杂的证书管理问题以及基于身份密码系统（IBC）固有的密钥托管问题。无需配对的无证书密码系统去除了耗时的双线性对运算,在不损安全性的同时进一步提高了无证书密码系统的效率。门限签名是标准数字签名扩展,由多个签名者共同为同一消息提供签名服务。基于无信赖者的秘密共享技术和无需配对的无证书密码技术,提出一个无需配对、无可信中心环境下的无证书门限签名方案。该方案可用于无可信服务器的分布式系统。分析表明,该方案具有较好的安全性、高效性且不依赖可信中心节点。

英文摘要：

Certificateless cryptography based on bilinear pairings resolves the problems of complicated certificate management in the Public Key Infrastructure （PKI） and inherent key escrow problem in the Identity-Based Cryptography （IBC）. Certificateless cryptography without pairing eliminates time-consuming bilinear pairings and further increases the efficiency of certificateless cryptography without losing safety. Threshold signature is an extension of the standard digital signature, in which several signers are required to provide signature service cooperatively for the same message. Based on secret sharing without a trusted party and certificateless cryptography without pairing, this paper proposes a certificateless threshold signature scheme without paring and trusted center, which can be adopted in distributed systems without trusted server. Analysis shows that this scheme is secure and efficient and does not rely on trusted center.