The Research Of Theory And Methods In Chaotic Encrypt Communication System

This paper introduces the fundamental theory of cryptography at first. Chaos theory will be introduced to the encryption of data flow. According to the chaotic system unique initial sensitivity,stochastic properties, improving traditional encryption algorithm, and raising a application method about building discrete chaotic system in the encryption of data flow based on continuous chaotic system. It raises more chaotic image encryption method of the application spatiotemporal chaos in the encryption of image data flow and the application of chaos in the encryption of data flow. These methods about the encryption of data flow can be expanded and integrated in further to be directed against modern data communications. Neural networks,hyper-chaos and so on will be introduced the encryption of modern data flow that slove some problems of traditional cryptography of simple and key length limited in modern encryption technology.It studied chaos heterogeneous synchronous and synchronous controller design, making use of principle of optimal control to realize synchronous controller design and analyzing synchronous problems of self delay chaos. On the basis of these theories, using the method of state observer research conducted for a class synchronous of nonlinear feedback hyper-chaos system and the application to secure communication in the system for disturbance.Chaos theory will be introduced encryption algorithm of images and voice. Through several typical chaotic system for mathematical calculations and simulation analysis, we improve traditional encryption algorithm. Through analyse the classical equations of the model of Duffing, we have seen chaotic system may arise bifurcation phenomena and chaotic motion phenomena. Introducing basic principles based on Duffing for chaos secure communication and giving circuit realizing and simulation. Theoretical analysis and simulation results indicate that this chaotic secure communication system has good confidentiality performance and realizing convenience. Raised a chaotic sequence image encryption technology based on Duffing, and through simulation prove this image encryption technology not only retains one-dimensional discrete chaotic system for the characteristics of high efficiency declassified, but also expand key space. Further enhanced the encryption system's ability of anti-decipher. Analysis of the safety of chaotic encryption.In voice realize chaotic encryption, Lorenz chaotic system will be calculated and analyzed through mathematical and simulation. Introduced several methods about voice encryption applications based on chaotic sequence. Presenting a method of voice chaos for secure communication based on Lorenz system. After the system to a fully synchronized, voice signal has no distortion. Encryption and decryption have achieved very satisfactory results. Using of chaos pulse sequence improved pulse code modulation technique. Although each pulse has the same shape, time interval is chaotic change between pulse , and realizing communication encryption. Through analysis we can find that because transmitter ultimately send pulse width is very narrow pulse sequence, the system applies to pulse radio communication system existly. Only need to add standard pulse generator and broadband antenna after the baseband processing.According to secure communication technology of CPWM and using discrete chaotic dynamics system to produce chaotic iteration. Using linear combination of chaotic iteration value and the digital information signal to control pulse width(duty cycle), digital information hiding in the digital pulse width; the receiver use detected pulse width and chaos synchronization iteration value can resume transmitter's information signal. The increased pulse signal power levels can enhance anti-interference. At the same time using synchronization principle of drive-response can ensure receiver and transmitter reach synchronization of chaotic iteration.Introduced a iteration algorithms of chaotic sequence and the design of generator, the advantage of chaotic sequence lies in different IFS can produce different chaotic behavior; For the same IFS, if different parameters, produced chaotic sequence is vastly different, and a major characteristic of the chaotic sequence is extreme sensitivity of the initial value; also, different rules of timing,fix rate for interference will produce different the chaotic sequence.Studying of the chaotic system of phase space technology in the application of secure communication. Phase space has extremely rich chaotic signal, through phase space signal realize chaos keying,expand bandwidth, raising confidentiality,increase the difficulty of tracking deciphered,give the structure of the circuit and simulation test results, to meet the design expected goal and ideal results. Combining Pangkalai thinking, raising thinking about chaotic phase trajectory through custom subspace produce thinking of pseudo-random chaotic sequence. Through this method produce pseudo-random sequence has better pseudo-random,dynamic adjustment,dynamic controllability,difficult track and crack and so on. So the chaotic secure communication has better control mechanism, better prospects application.Finally, a summary of the full text.