消息认证码(Message Authentication Codes,MACs)是保证消息完整性的重要工具.Bellare等人提出了称为XOR—MAC的消息认证码,界定了攻击者成功伪造的概率,从而证明了其安全性,但是他们给出的证明方法较为复杂.本文使用Game—Playing技术采用新的安全性定义证明了XOR—MAC的安全性,证明方法简单明了;在底层所使用的分组密码是伪随机置换的假设下,量化了该消息认证码与随机函数之间区分的概率.
Message Authentication Codes are very important tools to protect data integrity. XOR-MAC is defined by Bellare, who also gives a security analysis for it. But the security analysis they gave for XOR-MAC is complex. In this paper, we use the Game-Playing technique to give a new security analysis for XOR-MAC. We prove XOR-MAC secure, quantifying an adversary's success probability of distinguishing XOR-MAC from a purely random function in terms of the quality of the block cipher as a pseudorandom permutation.