具有代理重加密性质的自认证签密方案

摘要

对俞惠芳等的自认证签密方案(《计算机科学》,2010年第7期)进行分析,发现其中代理签密人可以恢复原始签密人的私钥.对此,基于双线性映射提出一个具有代理重加密性质的自认证签密方案,利用一个半可信的代理人,使对同一消息签密的解密身份可以在不同用户之间进行透明转换.与同类方案相比,该方案可以解决传统公钥密码体制的证书管理问题和身份密码体制中的密钥托管问题,同时具有安全性高、密钥长度短、计算量和通信量小的优点.%By analyzing Yu Huifang's self-certified signcryption scheme, this paper finds that the proxy can recover the private key of the original signcryptor, and proposes a self-certified signcryption scheme with the character of proxy re-encryption based on bilinear mapping. It makes use of a semi-trusted proxy to realize the transparent conversion between the different de-signcryptor's identities of the signcryption on the same plaintext. Compared with another scheme, the scheme proposed can eliminate the certification management in the traditional public key cryptosystem and the key-escrow in the identity-based system, and it has advantages of high security, short key, low computing complexity and communication costs.