Delay Chen Hyper-chaos With Varying Parameters And Its Application In Secure Communication

In this paper,considering the secure problems about the low dimensional chaos using in the secure communication,The hyperchaos have been regarded as a better scheme. and now, much research about hyperchaos is focusing on constructed by introducing new terms.the more positive lyapunov exponents,the more new term is needed to add in the system,and the system will became complex and difficult to analyzed.and the delay systems were considered to have the properties of infinite-dimensional state space, which can produce more positive lyapunov exponent without add other terms.Therefore,a new hyperchaos system is constructed by introducing an time-delay state feedback.Some basic properties,including the stability of the equilibria, hopf bifurcation, lyapunov exponent spectrum, phase diagram and so on,have been study Thoroughly.The existence of hyperchaos is verified with lyapunov exponent spectrum and power spectrum.In view of the output of the delay chen system carrying the information of the delay parameter,we proposed a method of changing the delay parameter in discrete time, we need to choosing proper time interval to change the delay parameter which is chosed by a pseudo random sequence.We found that change delay parameters of chen systems can effectively increase the size of the parameter space and improve the system’s ability to resist brute-force attack.At last,we analyzed the situation that delay chen hyperchaos using in the secure communication,with local impulsive synchronization. Combined the theory of impulsive differential equations with numerical analysis, a sufficient condition of pulse interval and coupling strength for synchronous are given.In conclusion, compared to the chen chaotic system, The delay chen hyper-chaotic can be better choice in the chaotic secure communication,with more complex dynamical behaviors and stronger anti-attack ability.