一个新的无证书环签密方案4

A New Certificateless Ring Signcryption Scheme

近年来,为了解决基于传统公钥密码系统中证书的使用问题和基于身份密码体统中固有的密钥托管问题,无证书公钥密码系统的概念被引进。文中基于双线性对提出了一个新的无证书环签密方案,使得消息能够以一种匿名的方式被发送并同时具有保密性和认证性,接收方仅知道消息来自于某个群体,但不能确认是这个群体中的哪个成员。在随机预言模型下,基于决定性双线性Diffie-Hellman困难问题假设,文中方案是安全的。较之传统的"先签名后加密"的模式,文中方案更加有效。

Recently, in order to eliminate the use of certificates in certified public key cryptography and the key-escrow problem in identi- ty based cryptography, the notion of certificateless public key cryptography was introduced. In this paper, a new certificateless ring sign- cryption scheme based on bilinear pairing is proposed. The message can be sent anonymously, authentication and confidentiality are guar- anteed simultaneously in the scheme. The recipient can be convinced that the message has been sent by one of the members in this group, but the actual sender remains unknown. The scheme is proved to be secure in the random oracle model under the hardness assumptions of the decisional bilinear Diffie-Hellman problem. Compared with the traditional ＂signature then encryption＂ paradigm,this scheme is more effective.