Chaotic Combination Synchronization And Its Application In Secure Communication

Chaos is a widespread phenomenon in nature,which is characterized by extreme sensitivity of initial conditions,quasi-random motion and high unpredictability.Since the discovery chaos system can be controlled,the research and application of chaos theory have been widely concerned.At present,the theory of chaotic synchronization control and its application in secure communication are also developing.The research of chaotic synchronization is of great significance for secure communications,considering the features of multivariate combination synchronization and diverse combinations,the application has natural advantages in secret communication direction,but at the moment,the combination synchronization control study between multiple chaotic systems is still less and relatively single and fixed,and the application of secure communication is not enough in-depth.This paper selects Chen system,Lü system,improved Lü system and Zhou system as the research objects,analyses dynamic behaviors of above four systems in detail,calculates the balance and stability of the system and analyses dissipation of system,through bifurcation diagram and the calculation of lyapunov index spectrum,the dynamic features of system with parameter changing is concluded,which have complicated dynamic behaviors.To expand the combination of the traditional way for the three drive a response,two driving two response and a drive three responses of three combination synchronously,the synchronization controller is designed respectively based on the lyapunov stability theory,the combination synchronization of system is realized,considering the particularity of the anti-synchronization,a single controller was designed to realize the anti-synchronization control of three kinds of combination synchronization.According to the circuit principle,four analog circuits of chaotic system are designed.The system circuit and anti-synchronization circuit are built with Multisim software.The waveform diagram is compared with the calculation results of MATLAB to confirm the correctness of the circuit design.Three chaotic secure communication schemes are designed on this basis:Multivariable secure communication scheme,part of the state variables x,y and z are used to encrypt the signal,and the rest are used to decrypt the signal,making full use of multiple variables to increase the difficulty of decoding;Multi-level chaos masking communication scheme,the information signal is superimposed with y variable to complete the first level of encryption,and then superimposed with z variable to complete the second level of encryption after scaling twice;Segmented encryption and secure communication scheme,the signals are divided into two sections based on the characteristics of the original signal and two sections according to the system variable x,and the segmented signals are respectively covered by variable y and variable z.The scheme made full use of the characteristics of multivariate combination synchronization to encrypt and decrypt information signals,which increases the difficulty of obtaining complete signals and has stronger confidentiality.