中文摘要：

线性复杂度和k错线性复杂度分别是度量密钥流序列的密码强度和稳定性的重要指标。通过研究周期为2^n的二元序列线性复杂度．提出将k错线性复杂度的计算转化为求Hamming重量最小的错误序列。基于Games-Chan算法．讨论周期为2^n的线性复杂度为2^n-9的二元序列的4错线性复杂度分布，并给出了其对应4错线性复杂度序列的计数公式。

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 and stability. By studying linear complexity of binary sequences with period 2n, it is proposed that the computation of k-error linear complexity should be converted to finding error sequences with minimal Hamming weight. Based on Games-Chan algorithm,4-error linear complexity distribution of 2^n-periodic binary sequences with linear complexity 2^n-9 is discussed, and the complete counting functions on the 4-error linear complexity of 2^n-periodic binary sequences with linear complexity 2^n-9 are presented.