针对基于身份的强指定验证者签名方案是不可授权的结论和基于身份的指定验证者代理签名方案设计,对两个方案进行安全性分析,首先证明了基于身份的指定验证者方案的签名是可授权的,然后证明了基于身份的指定验证者代理签名方案的签名是可伪造的,说明基于身份的器指定验证者签名方案的结论是不安全的;而基于身份的指定验证者代理签名方案的设计是不合理的。
Compared with ordinary digital signature, the designated verifier signature scheme makes it possible for a signer to convince a designated verifier that she has signed a message in such a way that the designated verifier cannot transfer the signature to a third party. In designated verifier signature scheme, no third party can even verify the validity of a designated verifier signature since it must use the designated verifier's secret key in verification. Recently, an ID-based strong designated verifier scheme, ID-based designated verifier proxy signature scheme, and partial cryptanalysis ware proposed. In this paper, we show that the designated verifier signature scheme is delegatable, and the designated verifier proxy signature is forgeable since construction of the proxy scheme is unreasonable.