基于耦合锯齿映射的时空混沌伪随机数发生器

基于近邻耦合锯齿映射的扩散和混乱特性,利用密码学判定,提出一种时空混沌伪随机序列产生方法.把由锯齿映射组成的近邻耦合映像格子作为时空混沌系统,各格点变量能同时输出独立的伪随机数.对参数β取不同值时弱耦合情况下伪随机数的概率密度函数和类随机性进行了数值分析,且对量化后的伪随机序列进行了周期特性、平衡性、相关性分析和NIST测试,结果表明,该序列有很好的密码学特性.在此基础上利用该伪随机数发生器构成一种简单的流密码,讨论了其安全性,发现基于近邻耦合锯齿映射的时空混沌伪随机数发生器能用来构造更高效安全的混沌流密码.

Spatiotemporal chaotic pseudorandom number generator based on coupled sawtooth map

Based on the diffusion and spatiotemporal chaos produced by coupled sawtooth map,a spatiotemporal chaotic pseudorandom number generator(PRNG) that determined by cryptography is proposed in this paper.A two-way coupled map lattice consisting of sawtooth maps is made to serve as the spatiotemporal chaotic system.Each lattice could produce an independent pseudorandom number simultaneously.The statistic characteristics of the pseudorandom number were investigated numerically during situations of weakly coupled such as stationary probability density function and random-like behavior with parameter β in different values.Furthermore,the cryptographic properties of the pseudorandom sequence such as period,balance,correlation were analyzed in details.The test of security using NIST test suite were analyzed as well.Both theoretical and experimental results show that the pseudorandom sequence of the spatiotemporal chaotic system possesses very good cryptographic properties.A simple stream cipher based on the proposed PRNG is constructed and its security is discussed.The proposed PRNG based on two-way coupled sawtooth map has been verified to be a good candidate for constructing a more secure and efficient stream cipher.