一种可证安全的基于身份门限代理签密方案

摘要

代理签名可以实现签名权利的委托,具有可认证性和不可否认性,然而却不能提供保密性.签密是一种将加密和签名结合在一起的技术,它同时具有两者的优点.利用双线性对技术,提出了一种在标准模型下有效的基于身份门限代理签密方案,并对方案的安全性进行了分析.最后,通过DBDH问题的困难性证明了方案的语义安全性,同时利用CDH问题的困难性证明了方案的不可伪造性.%The proxy signature allows a designated person, called a proxy signer, to sign on behalf of an original signer. It has the properties of authenticity and non-repudiation of message except confidentiality. Signcryption is a technique that can encrypt and sign data together in some way,while it has merits of them. This paper presented an efficient identity-based threshold signcryption scheme in the standard model and gave its security analysis in terms of bilinear pairing technique. At last, we proved its semantic security on the hardness of Decisional Bilinear Diffie-Hellman problem and its unforgeability on the hardness of Computational Diffie-Hellman problem.