Synchronization Of Hyperchaotic Chen Systems And Its Application In Secure Communication

Synchronization of chaotic systems and its application in secure communication is animportant topic in nonlinear science, and it’s also full of hopes and challenges to high-techareas in the new century. Based on the Lyapunov stability theory, combining the theoreticalanalysis with the numerical simulation, a video encrypting secure communication by usingfractional hyperchaotic Chen systems is proposed，then the synchronization of hyperchaoticChen systems with feedback controls and a single parameter modulation or multipleparameters modulation for secure communication schemes are investigated. The main work isas follows:Firstly, taking advantage of the randomness, boundedness and renewability of the chaoticsequences, a method of video encryption based on fractional order hyperchaotic Chen systemis proposed. In order to weaken the correlations between neighbor pixels, the video streamsare decomposed into images, then the positions of images’ pixels are scrambled by a loopalgorithm, the sequences of fractional order hyperchaotic Chen systems are used to encryptthe audio and video, so that the original video is encrypted effectively, We finally use the keyto decrypt the encrypted video. Simulations show that the method has a high efficiency andstrong encryption security.Secondly, based on the Lyapunov stability theory, hyperchaotic Chen systems aresynchronized via linear feedback controls and the parameter is identified using the adaptivecontrol techniques even though the parameter is unknown. Then a scheme of securecommunication using the single parameter modulation method is presented according to thesynchronization of chaos systems, and the results of continuous signal simulations verify thefeasibility of the method. Furthermore, some security analyses and noise robustness of theproposed secure communication schemes are given to show its feasibility.Finally, the multi-parameters modulation schemes for hyperchaotic Chen systems arestudied, and we synchronize the hyperchaotic Chen systems with unknown parameters bydesigning simple linear feedback controls. Meanwhile, a secure communication bymulti-parameters modulation is established, which modulates the discrete signal into the parameters by some rules and it can be identified successfully, and images as experimentalsubjects. The correctness of the theory, effectiveness and security of the digitalcommunication schemes are showed by numerical simulations in the end.