对SHA-256的初步统计分析

Preliminary Statistical Analysis of SHA-256

在SHA-256基本体制的基础上,利用统计推断和假设检验的方法对每一轮输出数据进行了0-1频率、0-1游程和0-1跟随优势方面的检测;并对每一轮的输出进行了二阶差分分析。在随机性方面验证了SHA-256安全性,同时也发现SHA-256的一些输出数据随机性并不是很好、不符合随机序列特性的一些地方,这些结果为进一步分析SHA-256算法、找到算法的漏洞奠定了基础。

This paper detects the 0-1 frequency,0-1 course and 0-1 following advantages based on SHA-256 system using statistic assertion and hypothesis testing.Meanwhile the second-order differential is applied to analyze the output of each turn.Security of SHA-256 is verified in the randomness aspect,thus finding some deficiency on randomness of cyclic output data,which is beneficial for further study on SHA-256 and lays the foundation for the loops of algorithm.