一类伪消息认证码的安全性分析

The Security Analysis of a Kind of Pseudo-Message Authentication Code

消息认证码是实现数据完整性和数据源认证的重要工具。本文分析了一类基于Hash函数设计的消息认证码的安全性,指出这类消息认证码在结构上存在极大的安全漏洞,攻击者可以避开对Hash函数的安全性分析,随意伪造消息。结果表明,如果不利用任何加密算法,在仅使用一个密钥的情况下,很难既提供消息认证又使得消息保密。

Message authentication code （MAC） is an important tool for data integrity and authentication. In this paper, we analyse the security of a kind of MAC, which is designed on the basis of the Hash function, and point out that MAC is so insecure that the attacker can fabricate messages without analysing the security of the Hash function. The result of analysis indicates that if we do not use any encryption algorithm, it is very difficult to provide message confidentiality as well as authentication by only a secret key.