强指定验证者代理签名的密码学分析及改进

Cryptanalysis and improvement of strongly designated verifier proxy signature scheme

对文献[12]提出的一个强指定验证者代理签名方案进行了安全性分析,指出该方案存在安全缺陷,不诚实的代理签名人能够恢复出原始签名人的私钥,从而能伪造原始签名人的签名或授权。在原方案的基础上提出了一个改进的强指定验证者代理签名方案,并对新方案的安全性和有效性进行了分析。结果表明:新方案满足可验证性和不可伪造性。

Through security analysis of strongly designated verifier proxy scheme proposed by Xiang et al,we found that their scheme had security leaks. The proxy signer can recover the original signerls private key and forge the signing capabilities of the original signer. On the basis of their scheme ,we proposed an improved strongly designated verifier proxy signature scheme and analyzed its security and efficiency. The result shows that this improved scheme can satisfy the verifiability and unforgeability.