Chaos Synchronization In Secure Communication Applications

As a special moving form of nonlinear dynamics system, chaos is a course of determinate and random-like, chaotic signals has the properties of ergodicity, aperiodic, uncorrelated, board band, noise-like and sensitivity to chaos system's initial conditions. These properties make the chaos signal be fit for applying in secure communication and information encrypting. In recent years, much attention has been paid on chaotic synchronization technology applied in secure communication. This paper mainly research the synchronization between two different chaotic systems and the application in secure communication. The realization of synchronization between two different chaotic systems, enlargeing the range of usable chaotic systems, increasing the difficulty of decryption, it has practical significance on the development and application of chaotic synchronization technology.This paper firstly researches and simulate the concept and properties(sensitive to initial value, Lyapunov exponent, power spectrum) of chaos; then research the theory and simulate the existing synchronization methods: the synchronization method by drive-response, active-passive, coupling, feedback, adaptive; at the same time, based on the above all, researching a chaotic synchronization method by nonlinear matching terms feedback, and deducing the theory of this method, then realizing the synchronization between the different chaotic systems.This paper also researches the scheme of secure communication, based on the synchronized systems, simulating the secure communication systems by the scheme of chaotic masking and chaotic parameter modulation. In the chaotic masking secure communication scheme, designing a method that do some function transformation to the useful signal, it will increas the difficulty of decryption, enlarge the space of key and can be modulated effectively, the simulation results show that this method is feasible.In order to accelerate the course of practicality, this paper uses the FPGA to design, download and test the chaotic masking secure communication system based on the synchronization method by drive-response technology, finishing forming the model of secure communication system based on the chaotic synchronization technology, and approving this model design scheme and realization method is right via practice.