Abstract: In the cryptology ,the Hash function can be used in the data integrity and the news authentication as well as the digital signature，SHA-256 is one kind of Hash function which is used the most widespread. This article aims at SHA-256, We carry on the random test as well as the avalanche effect test to it with χ2 text in the statistical examination method and give the analysis discussion to the test result .Besides,we pointe out some deficiency in this algorithm.

摘要： 密码学中Hash函数能够用于数据完整性和消息认证以及数字签名，SHA-256是使用最广泛的一种Hash函数。本文针对SHA-256，用已有统计检测方法中的χ2检验对其进行了随机性测试以及雪崩效应的测试，并对测试结果进行了分析讨论，指出了该算法中的一些不足之处。