为了研究XOR消息认证码(XOR-MAC)的结构,从泛Hash函数和伪随机函数的视角,使用共享随机函数模型对其进行了分析.将XOR-MAC拆分为伪随机函数和泛Hash函数两部分,然后证明这两部分满足一定的性质,最后将其看成是一种将伪随机函数应用到泛Hash函数上的Carter-Wegman类型的消息认证码,并基于信息论给出了简洁的XOR-MAC安全性证明.借助这一思想可以非常容易地设计新的消息认证码.
In order to study the construction of X0R message authentication code (XOR-MAC), we analyse it from the view of universal Hash and pseudo-random function, using shared random funciton model. Firstly, XOR-MAC is splited into two parts: a pseudo-random funtion and an universal Hash. Secondly, this two parts can be proved to have certain properties. Finally, XOR-MAC is regarded as a kind of Carter-Wegman MAC by adopting a new method that applies a pseudo-random functions directly to the output of an universal Hash family. And we give a simple security proof of XOR-MAC based on information theory. The most important thing is that many new MACs can be easily constructed using this idea.