一些可证安全签名方案的密码学分析

最近，Okamoto提出一个在标准模型下可证安全的签名方案，VictorK．Wei等人提出两个在标准模型下可证安全的短签名方案。在本文中，我们指出这三个方案在多用户环境下是不安全的，不能抵抗强密钥替换攻击。在这种攻击中，一个敌手能够生成新的公钥满足合法签名者生成的合法签名。

Cryptanalysis of Some Provably Secure Signature Schemes

Recently,Okamoto and Victor K.Wei et al.proposed provably signature scheme in the standard model and two provably short signature schemes in the standard model respectively.In this paper,we show that the three schemes are all insecure against strong-key substitution attacks under the multi-user setting.In this attack,an adversary can generate a new public key satisfying legitimate signatures created by the legitimate signer.