高效的基于身份的代理签密方案

摘要

代理签密使原始签密人可以将其签密权力委托给代理签密人,然后代理签密人代表原始签密人签密指定的消息.为了更好地实现代理签密的公开验证性和前向安全性,利用椭圆曲线上双线性对提出一个基于身份的代理签密方案.分析表明,在ECDLP问题和CDH问题是困难的假设下,该方案是安全的.方案既保持了基于身份签密的优点,又具有代理签名的功能,只有指定的接收者才能从密文中恢复消息.并且同时具有前向安全性和公开验证性,适合于应用.%Proxy signcryption is useful when an original signcrypter needs to delegate his or her signcrypting capability to a signcrypter, and the proxy signcrypt messages on behalf of the original signcrypter. To solve the problem of no forward security and public verifiability, this paper proposed an identity-based proxy signcryption scheme from bilinear pairings. Analysis shows that the scheme is secury, assuming that ECDLP and GDH problem are hard. The new scheme not only has the function of proxy signature scheme, but also has the advantage of identity based signcryption scheme. Only the intended recipient can recover the plaintext from the ciphertext. What' s more, the scheme provided forward security and public verifiability and it is more propitious to applications in society.