一种改进的抗碰撞散列函数构造算法

An Improved Anti-Collision Hash Function Construction Algorithm

针对MD5和SHA等传统散列函数易发生碰撞的问题,在分析散列函数碰撞机率的基础上,提出一种改进的抗碰撞散列函数构造算法。算法利用元胞自动机的状态离散性和并行迭代的特性,在分析ECM(Encryption Checksum)散列迭代结构的基础上,对ECM散列迭代结构进行改进。通过在压缩函数运算之后,进入ECM迭代之前,进行一次初等元胞自动机变换,以此增强散列函数的随机性,解决易碰撞的问题。仿真结果表明,与其它散列函数相比,改进的散列函数具有更好的散列特性和抗碰撞性能。

For the problem that traditional hash functions such as MD5 and SHA will collide easily, on the base of analyzing the collision probability for hash function, we proposed an improved hash function construction algorithm. With the characteristics such as state discrete and parallel iteration for cellular automata, on the base of analyzing the ECM （Eneryption Checksum） iterative structure, we improved the ECM iterative structure. After the computation of compression function and before the ECM iteration, we conducted an elementary cellular automata transformation to enhance the randomness of hash function and solve the problem of collision easily. Simulation results show that the improved hash function has better hash characteristics and anti - collision performance compared with other hash functions.