Multiple-Image Encryption Algorithm Based On Block Rotation

The rapid development of the Internet not only brings convenience to people,but also poses a threat to information security.Among them,images are an important carrier of information,and their transmission frequency and scale are showing explosive growth.How to protect the integrity and security of images in the face of the challenges of a sharp increase in image data volume,enhanced computing power,and improved hacker attack capabilities is one of the urgent issues that researchers need to solve.The image encryption algorithm based on block rotation has advantages such as simple operation,sufficient scrambling,and intuitive transformation.To solve the problems of limited capacity and weak security of existing encryption algorithms,two multi image encryption algorithms based on block rotation are proposed by ingeniously utilizing the three-dimensional features of multiple images to expand and innovate block rotation.The main research content is as follows:(1)A multiple-image encryption algorithm based on dice-rotation model is proposed.Firstly,aiming at the problems of traditional one-dimensional chaos,a multi-parameter and wide-range improved chaotic system is designed;Secondly,inspired by the dice game,the dice-rotation model is established,including single dice rotation and multiple dice rotation;Finally,combined with the improved chaotic system,a complex relationship is constructed from the mathematical theory,that is,diffusion is carried out by using forward addition and modular operation,so as to complete the whole image encryption process.(2)A multiple-image encryption algorithm based on block rotation and dynamic stereo S-box is proposed.Firstly,according to the three-dimensional characteristics of multi-image data,the rotation of image blocks,layer rotation and co-rotation are defined to increase the block size and block form;Secondly,in view of the shortcomings of the traditional S-box,a dynamic three-dimensional S-box is designed as a nonlinear element to replace the diffusion;Finally,the improved chaotic system is used to shift XOR to further enhance the encryption effect.The experimental simulation and comparative analysis of the above two algorithms show that the two algorithms can encrypt multiple interactive images at once,and have excellent performance in key security,statistical performance,resistance to various attacks and robustness.There are 49 pictures,30 tables and 128 references in this thesis.