Encryption Algorithm Based On Chaotic Mapping Studies

With the increasing development of the computer and network technology, information security has become a hot spot and key issue of the study. Because of the complexity of security functions and various attack means, there is an urgent need to study and develop more secure, efficient, reliable information security technology. The chaotic theory is introduced into the field of information security, which is one of current international frontier topics of the fusion of nonlinear science and information science. Chaos and cryptography have a natural relation and some similarities in structure, which enlighten chaos applied to the field of cryptography. Example, the random characteristic of chaos and the sensitivity to system parameters correspond to the confusion characteristic of traditional encryption system; the orbit mixing characteristic of chaos corresponds to the diffusion characteristic of traditional encryption system. Thus, the excellent mixing characteristic ensures that chaotic encryption algorithms are as good as traditional encryption algorithms.The development of chaos is based on the research of specific chaotic systems. Chaotic systems which the paper mainly research include one-dimensional piecewise linear chaotic map, chebyshev chaotic map, logistic chaotic map which are used to design random sequence and Hash function. First, the paper uses cryptography characteristic of chebyshev chaotic map to design a pseudo-random sequence generator of double chaotic system and analyze performance of the chaotic system. The result demonstrates that the pseudo-random sequence generator has the best performance. Then, the paper uses one-dimensional piecewise linear chaotic map and the relation knowledge of traditional cryptography to design Hash function and analyze it. The result shows that the algorithm has the high sensitivity to initial data and the stability of confusion and diffusion.