标准模型下基于身份的环签密方案

签密是一个同时提供认证性和保密性的密码学术语,而与分别签名和加密相比,它却具有较低的计算成本.环签密除具有签密的一般属性外还具有匿名性,它允许任一用户代表一组用户进行签密,却不知道真正是谁生成了该签密.提出了一种有效的标准模型下基于身份的环签密方案,利用CDH问题和DBDH问题的困难性,证明了方案在适应性选择消息和身份攻击下的不可伪造性及在适应性选择密文攻击下的不可区分性.

Identity-based Ring Signcryption Scheme in the Standard Model

Signcryption is a cryptographic primitive which provides authentication and confidentiality simultaneously with a computational cost lower than signing and encryption respectively. The ring signcryption has anonymity in addilion to authentication and confidentiality, which allows any user to choose any set of users that includes himself and signcrypt messages without revealing who in the set has actually produced it. This paper presented an efficient identity-based ring signcryption scheme in the standard model, which proves its indistinguishability against adaptive chosen ciphertext attacks and existential unforgeability against adaptive chosen message and identity attacks in terms of the hardness of CDH problem and DBDH problem.