Research On Synchronization Technology For Chaos Secure Communication

With the development of science and technology, information age has come. While people enjoy the changes and the conveniences brought by information technology, they also have to endure a serious of problems due to information juggling, information leaking and information falsifying. Therefore, how to realize the secure communication becomes the concern of people. Now classical cryptography has been studied broadly and many decryption methods have been declared, hence people have to look for the new and more effective secure communication mechanism to deal with the problem on communication security. Chaos signal has many good characteristics, which make it very suitable to be applied to secure communication. Nowadays chaos secure communication has become the research hotspot. Chaos synchronization is the key for chaos secure communication, and corresponding researches provide the technology support for the realization of chaos secure communication. Therefore, this paper is schemed as follow:1. Based on Backstepping design method, which can design Lyapunov function systemicly and structuredly, this paper researches the problem on the synchronization of a class of chaotic system. First a series of Lyapunov functions are constructed step by step grounded on the recursive design idea. Then a driver is designed to realize the chaos synchronization. The method proposed in this paper provides a systemic and structured design approach for chaos synchronization and has big applicability.2. Based on the classical sliding model design method, a driver is obtained to make the synchronization error track stay on the sliding surface constructed. For the sliding surface constructed is insensitive to the uncertainty of system parameter and the outside disturbance which satisfies parameter matching condition, the synchronization of uncertain chaotic system with disturbance can be realized effectively. However, the existence of dithering in system will do harm to its synchronization performance. Therefore, the dynamic sliding model design method is proposed to handle such problem. Corresponding simulation results show its superiority.3. A neural network method is presented to design chaos synchronization driver. Neural network has the strong ability to approximate the nonlinear function. However, there exists the contradiction between its complexity and its approximation ability. The neural network synchronization driver with simple structure is difficult to realize the chaos synchronization by itself. Hence, the hybrid synchronization method with more drivers is proposed. For this method, a master driver is designed to realize synchronization of chaotic system in ideal state and a neural network assistant driver is designed to compensate the dynamic synchronization error to enhance the tracking precision, two drivers cooperate together to realize the synchronization of uncertain chaotic system with disturbance. Corresponding simulation results show its superiority.4. Based on impulsive design method, this paper researches the problem on the chaos synchronization of a hyperchaotic system. First, the realizable synchronization condition is given via theory analysis. Then, a serious of intermissive synchronization impulse is designed to let the slave system synchronize to the master system. Considering the little information contained in the impulsive synchronization driving signal, such method can be used to increase the security of communication system.5. Based on adaptive design method, which can design synchronization driver without using the information of system parameter, this paper researches the synchronization of hyperchaotic system. First, an adaptive method via the driving vector and an adaptive method via the single driving variable are given for the design of the driver to realize the chaos synchronization without using the information of system parameter. Then, the comparison and the analysis for the two adaptive methods are presented. Those methods provide effective ways to realize the chaos synchronization when the information of system parameter can not be obtained.6. Based on chaos synchronization technology, this paper proposes a chaos secure communication scheme. Two channel technology is adopted to enhance its security, and the digital switching technology is adopted to enhance its anti-jamming ability. Simulation results are given to show the effectiveness of the scheme proposed. Then, the comparison and the analysis are given for a classical chaos secure communication scheme and the scheme presented in this paper when the channel noise disturbances exist. Corresponding simulation results show the superiority of the scheme proposed by this paper, which has some engineering practical value.