无随机预言机下的指定验证者代理签名方案

在指定验证者代理签名中，原始签名者把自己的签名权力授权给一个代理签名者，后者可以代表前者签名消息，但是仅仅只有指定验证者能够相信签名的有效性。已知的指定验证者代理签名方案的安全性证明都是在随机预言机模型中的，该文中基于Waters签名方案，首次提出无随机预言机下可证安全的指定验证者代理签名方案。在弱Gap Bilinear Diffie-Hellman假设下，证明所提方案能够抵抗适应性选择消息攻击下的存在性伪造。

Designated Verifier Proxy Signature Scheme without Random Oracles

In a designated verifier proxy signature scheme, the original signer delegates his signing capability to the proxy signer in such a way that the latter can sign messages on behalf of the former, but only designated verifier can believe the validity of the signatures. The security of the known designated verifier proxy signature schemes is proven in the random oracle model. In this paper, based on Waters signature scheme, the first designated verifier proxy signature scheme is presented and is provably secure without random oracles. The proposed scheme is proven secure against existential forgery in adaptively chosen message attack under the weak Gap Bilinear Diffie-Hellman assumption.