Digital Secure Communication Based On Chaotic Synchronization

Chaos theory is the most important discovery in physics in the 20th century, the main purposes for investigating chaos in theory include uncovering its natures, depicting its basic characters, understanding its dynamical behaviors, controlling and utilizing it to serve people. With the further research in chaos theory, chaotic secure communication is becoming the advanced field in modern communication technique. Because of the property including non-period, consecutive BW spectrum and noise-like, chaotic signal is apt to secure communication. And chaotic synchronization, which is the pivotal issue of chaotic secure communication, has been the important content of the research in nonlinear complex science recently.This thesis, at the beginning, introduces the origin, applications and current situations of the chaotic synchronization and the secure communication used chaotic synchronization. Then, the analysis of basic theory of chaos such as definition of chaos, properties of chaos, definition of chaotic synchronization and Lyapunov exponent of chaos and some mathematics knowledge used on the study of chaotic synchronization. The methods of chaotic synchronization, such as PC synchronization, coupled synchronization, self-adaptive synchronization, observer synchronization and generalized synchronization, are analyzed. The proposed numerical simulations verify the corresponding theoretical results; these indicate that the chaotic synchronization has a good application in the secure communication. The researching key to application for digital chaotic secure communication is the strict chaotic synchronization method. Compared and analyzed methods of chaotic synchronization, because they can't arrive strict chaotic synchronization in these synchronous process, so these process can't be apply in the digital communications directly. This thesis puts forward a new method on these the foundation on these methods, which can make these methods applied in the digital communications. At last, based on an actual communication platform, using VC as the basis of encryption approach for text, a chaotic text secure communication system is constructed using chaotic synchronization. The establishment of synchronous...