Chaos Synchronization Theory And Cryptography

Since the 1990s of 20^th century, the idea of using chaos systems to the secure communication has attracted more and more attention. The use of chaos in the secure communication depends on the natural connection between the two research areas. Some characteristic of chaos satisfies that of the secure communication. Whereas, the secure characteristic of the communication requires the secure system possesses the chaotic character. As for the application of chaos in secure communication, there are two different kinds. One is the chaotic secure communication based on the analog system (mainly based on the idea of the chaotic synchronization). The other is the chaotic cryptology based on the digital system.The chaotic system has nice characteristic of secure communication, such as randomness, the extreme sensitivity to the parameter and the initial value. Meanwhile, chaotic system can be controlled, Chaotic Synchronization.The article contains 4 parts. The main content is that we analyzed a new method of Synchronization, and this method is applied to chaos masking secure communication system.Firstly the development and significance of chaos are introduced. The general requirement of communication system and the application potential in secure communication are expatiated. The chaotic synchronization secure communication methods home and abroad arealso summarized, including: chaotic masking, chaotic switching, chaotic modulation, and so on.Secondly, we deeply discussed various chaos synchronization methods. The main results are (1) the methods to obtain synchronization: Pecora-Carroll synchronization, driving-response synchronization, feedback synchronization, self-adept synchronization and couple synchronization. We also introduce the way that chaos synchronization is put into use and point out some problems should be solved.Then the features of existing chaos synchronization methods are analyzed. A novel chaos synchronization methods is presented, which has the fellow advantages: synchronization can be realized for not only alike-structure chaos system but also different- structure chaos system, not only applying to continuous system but also to discrete system, it is not necessary to consider the initial conditions in synchronization, and no necessary to calculate conditionally Lyapunov exponent. A lot of simulation results indicate the effectiveness of the method.Finally the novel chaos synchronization method is then applied to chaos masking secure communication system and simulation is performed. Many simulations indicate the validity of the method.