Abstract: The inherent defect of HMAC（Hash-based Message Authentication Code） algorithm is analysed in this paper. The forging attack triggered by HMAC parameters is described as well. Aiming to deal with this problem, a novel HMAC algorithm based on chaotic maps is presented, which can generate HMAC parameter values through chaotic iteration. The approach can ensure the dynamic parameters, as the chaotic system is sensitive to the initial variables and unpredictable to final values. Therefore, it can effectively resist the forging attacks as a result of enhancing HMAC algorithm security performance. Finally, the algorithm simulation and analysis indicate that both designing HMAC algorithm and embedded hash function should meet the security conditions to ensure the security of entire algorithm.

Key words: Hash-based Message Authentication Code（HMAC）, chaotic map, hash function, forging attacks

摘要： 分析了HMAC（Hash-based Message Authentication Code）算法存在的固有缺陷，给出了针对HMAC参数的伪造攻击实例。在此基础上，提出了一种采用混沌映射的构造HMAC的算法，该算法通过混沌迭代生成HMAC参数值，混沌系统的初值敏感和不可预测性确保了参数值的动态性，从而有效抵抗伪造攻击，提高HMAC算法的安全性能。算法仿真与分析表明构造HMAC算法需要满足的安全性要求及嵌入的hash函数需满足的安全性条件。

关键词: 基于哈希的消息认证码（HMAC）, 混沌映射, hash函数, 伪造攻击