摘要
本文利用母函数的方法对几种经常用到的特殊的流密码——周期序列的补序列,周期序列的部分和序列,逆向序列和有限生成序列进行了研究,给出了它们的极小多项式,周期和母函数。对有限生成序列讨论了线性复杂度变化情况和联结多项式次数不变的情况下两个生成序列之间的关系。
Several kinds of stream ciphers-complement sequences of period sequences,partial sum of period sequences, inverse order sequences and finitely generated sequences, are studied by using techniques of generating functions. Their minimal polynomials, periods, as well as generating functions are given. As to finitely generated sequences, the change of their linear complexity profiles as well as the relationship between the two generated sequences under the case in which the degree of connected polynomials are fixed, are discussed.
关键词
流密码
母函数
补序列
B-M算法
Stream cipher
Generating function
Complement sequence
Partial sum quence
Inverse order sequence
Finitely generated sequence
B-M algorithm