Research On Image Encryption Algorithm Combining Chaotic System And Compressed Sensing

With the development of internet technology,the transmission of information through the internet has become an essential part of people’s daily lives.As a special form of information,images carry richer information and are widely used in various fields.Information is faced with security issues during the transmission process.If images containing personal privacy,corporate secrets,and even national political and military information are leaked,it will have unpredictable consequences for individuals,businesses,and the country.In addition,with the increasing amount of image data in medical and military fields,image encryption requires a lot of time,and the preservation and transmission of ciphertext images consume many resources,so studying image encryption and image compression algorithms is of great significance.Due to the characteristics of chaotic system,it is very suitable for application in the field of image encryption.The appearance of compressed sensing technology has greatly improved the image compression performance.In view of the problems such as the lack of security of the current image encryption algorithm,this paper combines the chaotic system and compressed sensing technology to design an image encryption algorithm that considers both cncryption efficiency,security and compression performance.The main work includes:(1)An image encryption algorithm combining SCCM map and compressed sensing is proposed,in which SCCM map has the characteristics of fast iteration speed and strong chaos.In this algorithm,a method of generating keys through 2D-DCT and SHA-256 functions is designed.This method has strong plaintext sensitivity,making the overall encryption algorithm capable of resisting selected plaintext attacks.Before compressed sensing,the sparse matrix is scrambled by through the zigzag confusion algorithm,then use Arnold trnasformation and modular diffusion operations to improve the security of the encryption algorithm.The experiment shows that the algorithm has fast execution speed,high security performance,and improves the quality ofreconstructed images.(2)An image encryption and hiding algorithm combining hyperchaotie system and compressed sensing is proposed.The key to the algorithm is jointly generated by SHA-512 function and 2D-IDCT.In compressed sensing,partial random block weighting matrix is used as the measurement matrix,the information of the original image is destroyed by scrambling and diffusion technology,and the security of the encryption algorithm is improved by using DNA encoded triploid mutation technology.Finally,the obtained ciphertext image is embedded into the carrier image through IWT and bit plane decomposition technology,reduce the probability of ciphertext images being attacked.Experiments have shown that this algorithm has high security while ensuring the visual effect of ciphertext images.Even if the encrypted image is extracted from the carrier image,it is difficult to obtain effective information from the encrypted image.This article mainly focuses on image security issues and proposes two image encryption algorithms.The algorithm proposed in Chapter 3 can achieve image compression and encryption,which is suitable for images with large data volumes.The algorithm proposed in Chapter 4 incorporates image hiding algorithms to further improve the security of images during transmission.Through experiments,it has been proven that the two encryption algorithms have high security and can effectively protect the security of image transmission.