中文摘要：

线性复杂度和k错线性复杂度是度量密钥流序列的密码强度的重要指标。该文通过研究周期为2n的二元序列的线性复杂度，将k错线性复杂度的计算转化为求Hamming重量的最小的错误序列，基于Games．Chan算法，分析了线性复杂度为2n，周期为2n的二元序列的5错线性复杂度的分布情况，给出了5错线性复杂度为2n-3,2n-3＋1和2n-2-2n-4的二元序列的计数公式，并通过计算机编程进行了验证。

英文摘要：

The linear complexity and the k-error linear complexity of a sequence have been used as important measures of key stream sequence strength. Based on Games-Chan algorithm, this paper analyzes on 5-error linear complexity distribution of 2n-periodic binary sequences with linear complexity 2n by studying linear plexity of 2n-periodic binary sequences with linear complexity is, and, gives the counting functions and veri- fies them by a number of examples with computer.