Memristive Hyperchaotic System And Its Application In Image Encryption

In 1971,Chua predicted the existence of memristors and he thought that the memristor is the fourth basic circuit component juxtaposed with resistors,capacitors and inductors.However,in the following thirty years,there had been no breakthrough in the field of memristors.Until 2008,with the progress of modern nanotechnology,HP Labs implemented the physical memristive devices for the first time.Memristors exsit promising application in the fields of neural networks,digital logic,nonvolatile memory and chaotic circuits due to the nanoscale size,low power consumption,switching characteristics,unique memory characteristics and nonlinear characteristics.In this paper,the flux controlled memristor equivalent circuit model is introduced.In the meanwhile,the non-volatility and circuit characteristics are analyzed.Secondly,a memristive hyperchaotic system is established based on the flux controlled memristor and the hyperchaotic state of the system can be determined by the calculation of Lyapunov exponent and Lyapunov dimension.Next,the optimized factor is introduced into the memristive hyperchaotic system.It is found that the system state and attractor characteristics can be controlled by the optimized factor,and then the optimized factor is implemented in the hardware circuit.Finally,a new image encryption algorithm is proposed based on the memristive hyperchaotic system,and the anti-attack performance of the algorithm is analyzed.The content and innovations of this study are as follows:Firstly,the equivalent circuit model of the flux controlled memristor is introduced in this paper.The circuit characteristics of the memristor are studied and the non-volatile characteristics of the memristor are analyzed by the POP(Power-Off Plot)method.Next,a novel hyperchaotic circuit is proposed by introducing memristor feedback in a simple chaotic circuit of Lorenz-like system.Dynamic analysis shows that it has infinite equilibrium points and multistability.Additionally,the symmetrical coexistent attractors are investigated.Memristive hyperchaotic system is implemented by analog circuits,and the effectiveness of the system has been verified.Additionally,it is found that the hidden attractors can be obtained by adding an optimized factor to the memristive hyperchaotic system.Specifically,when the optimized factor is varying,the corresponding hidden attractors of the system are symmetrical and can convert between double scrolls and a single scroll.Finally,the optimized factor is implemented by hardware circuits.Finally,a color RGB image encryption algorithm based on memristive hyperchaos is proposed.The encryption process incorporates scrambling and diffusion operations,and the shift operation is closely related to the selected key information,which increases the complexity of encryption.The anti-attack performance of the algorithm is analyzed and the randomness of the memristive hyperchaotic pseudorandom sequence and the linear congruence pseudorandom sequence are compared.Image encryption software is realized by the Open CV library and the MFC framework.