使用双线性对的指定验证人代理签密

指定验证人代理签密要求代理签密人只能对发给指定验证人的信息代理原始签密人签密，而其他人则不能代理原始签密人签密。基于指定验证人代理签密和自认证密码系统的理论，一个使用双线性对的指定验证人代理签密被提出。该方案具有以下特点：在传送代理签密时，没有必要传送消息，因为指定验证人能从代理签密中正确恢复出消息；能够在逻辑单步内同时验证代理签密的有效性和公钥的真伪；克服了密钥托管问题；不需要对公钥显式认证。与已有方案相比，新方案仅仅需要2次pairings运算，效率很高。

Designated-verifier proxy signcryption from bilinear pairings

Designated-verifier proxy signcryption requires that only proxy signcrypter on behalf of the original signcrypter can generate the proxy signcryption which is sent to the designated-verifier.Based on the theory of designated-verifier proxy signcryp-tion and self-certified cryptography,a designated-verifier proxy signcryption from pairings is proposed.The scheme has the follow-ing features：The signing message is unnecessary to transmit,since the designated-verifier can recover it from the proxy signcryp-tion;the tasks of verifying the authenticity of public key and validating the proxy signcryption are carried out simultaneously in a single step;there is no key escrow problem;there is no explicit authentication to public key by certification.The new scheme only requires two bilinear pairings operations,so its efficiency is higher than the existing ones.