基于符号动力学的0-1序列发生器

Bit Sequence Generator Based on Symbolic Dynamics

采用数字混沌系统进行保密通信比采用连续流混沌系统更易于控制和同步以及软硬件的实现,而且具有较高的保密性。该文提出一种0-1序列发生器的设计方法,该方法通过混沌系统产生混沌序列并粗粒化,从而产生出符号序列(即0-1序列)。为了克服计算机有限精度造成的短周期,对生成的混沌序列进行了周期性修正,这样不仅增大了序列的周期,而且使得序列的周期可度量。用两个混沌系统产生的符号序列进行异或运算后作为最终输出,从而进一步增加了输出序列的随机性,也使得输出序列更加难以破译。理论研究和模拟结果表明,该序列发生器具有较好的随机性并且便于软硬件的实现。

Comparing with the continuous stream chaotic system,the digital chaotic system applied to the secure communication is not only easy to control,synchronization and design but also is fairly good in security.This paper presents a method of bit sequence generator based on chaotic system,In order to overcome short period resulted from the finite precision in practical application,we amend the output of chaotic sequence periodically so as to lengthen the period of the sequence and make the period of the sequence can be measured.Moreover,the bit sequence generated by the XOR operation of two chaotic sequence is used as the final output sequence,by this method,the randomness of the output sequence will be increased thus difficult to decrypt.The computer simulation results also show that this bit sequence generator has good randomness properties and can be implemented easily in both software and hardware.