Research On Image Encryption Technology Of Random Algorithm Based On Hyperchaotic System

In recent years,the speed and frequency of information transmission between people and people,and between people and the Internet of Things has been increasing.As an information medium,image information has more advantages than traditional text and audio information,which contains more information and is more vivid and intuitive.However,if the images are illegally accessed or even used for crime during transmission,it can bring a great negative impact on both sides of information transmission.Therefore,the security of the network transmission of images becomes particularly important.Chaotic signals have properties such as pseudo-randomness and ergodicity,which can be naturally used as encryption sequences for image information encryption,and chaotic confidential communication is gradually applied to image encryption.However,as the research progresses,the security vulnerabilities of the inherent chaotic encryption algorithm are slowly exposed,especially since it cannot well resist the selective plaintext attack.Therefore,the study of chaotic image encryption algorithms is of great practical significance.In this paper,we study the encryption algorithm based on chaotic image encryption theory.First,we introduce the basics of chaotic systems and list several common chaotic systems,and explainthe basic principles of cryptography and chaotic cryptography.Secondly,the four-dimensional Lorenz hyperchaotic system is studied in depth and discretized using the Longacurta method,and the autocorrelation analysis and power spectral density analysis of the encrypted sequence is performed.Finally,a random algorithm image encryption technique is proposed to make different image color blocks use different encryption algorithms by introducing random variables,so that the ciphertext after each encryption is different without changing the key,forming a diffusion-diffusion-displacement-diffusion random algorithm image encryption.The results show that the proposed super-chaotic random algorithm image encryption technique can withstand brute force,statistical analysis,and mathematical analysis attacks,and is highly secure,especially against the plaintext selection attack.