Research On Color Image Encryption Based On A Simple 4D Hyperchaotic System

With the improvement of science and technology,information transmission is becoming faster and more diverse.As an important carrier of information,color images play an important role in the transmission of information.However,information leakage and cracking occur frequently.Therefore,the encryption and decryption of images become important in secure information transmission.For the high sensitivity to initial conditions,strong pseudo-randomness and other characteristics,chaotic systems are widely used in digital image encryption.and related research has developed rapidly.In this paper,a four-dimensional(4D)hyperchaotic system with simple structure is constructed firstly.Then the dynamic characteristics are analyzed.Based on the system,two color image encryption schemes are proposed,and experimental simulations and performance analysis are performed.The work is as follows:1.According to the structure of the 4D hyperchaotic system,a state variable is added to the Bao system and the structure of the equation is adjusted to construct a novel 4D hyperchaotic system with simple structure.The phase trajectory diagram,Lyapunov exponent diagram,bifurcation diagram and time domain diagram are analyzed.Simulation results and theoretical analysis show that the proposed system has simpler structure and more complex chaotic characteristics,and it is suitable for image encryption.2.A new color image encryption scheme is studied based on the 4D hyperchaotic system and opposite diffusion.The system generates the required sequence for encryption.The encryption algorithm encrypts the three components(RGB)of the color image separately.The use of keys related to the plaintext solves the problem that the keys have nothing to do with the plaintext,and enhances the algorithm's ability to resist attacks in the plaintext.The diffusion process adopts a new method-opposite diffusion.The diffusion process can be completed after one cycle period,which reduces the calculation complexity and makes the diffusion more uniform.The Arnold matrix is multiplied to the pixel and then the modulus operation is applied to change the pixel value.Theoretical analysis and simulation results show that the encryption scheme has better performance in information entropy and resistance to differential attacks,and comparing the results of related references.3.A new color image encryption scheme is developed based on the above 4D hyperchaotic system and single-cycle diffusion.The system generates the required sequence for encryption.The Arnold matrix is multiplied to the pixel and then the modulus operation is applied to change the pixel value.The diffusion process uses a new method-single cycle diffusion.The diffusion method solves the problem that there is no correlation between the RGB three components in the previous diffusion study,reduces the correlation between adjacent pixels of the ciphertext image,and enhances the connection between the plaintext and the ciphertext,so that the method has better performance in resists differential attacks.Theoretical analysis and simulation results demonstrate that the encryption scheme has good security and resistance to violent attacks.