The Research On Image Encryption Technology Based On Chaos

With the rapid development of the Internet and digital technology,the interaction of information on the Internet has become more and more frequent in various fields.As one of the most common carriers of information on the Internet,digital images can not only store a large amount of information efficiently but also shows the emotional content of the information well.The visual data it contains,however,is easily exposed to the risk of leakage if the digital image is captured by others during the transmission process.As a result,it is crucial to safeguard the security of image information,and image encryption technology has received a lot of attention as a successful method of doing so.Due to its nonlinear nature,chaotic system has many excellent characteristics,such as ergodic,initial condition sensitivity and unpredictability.For the above characteristics,researchers combine chaotic system with image encryption technology to obtain chaotic image encryption algorithm.To explore more digital image encryption strategies,this paper makes use of chaotic sequences generated by chaotic systems and proposes three chaotic image encryption algorithms,the details are as follows:(1)A chaotic magic cube transforms image encryption algorithm(CMCT-IEA)based on no-equilibrium chaotic system is proposed.Firstly,a new no-equilibrium chaotic system is used to generate chaotic sequences.Secondly,based on the size of the plain image,a pre-processing operation mode is utilized to transform the pixels in the plain image into a three-dimensional magic cube pixel matrix and generate the appropriate key.Then,the three-dimensional chaotic matrix is used to diffuse and scramble the three-dimensional pixel matrix.Finally,the cipher image is obtained after three rounds of permutation-diffusion operation.Different from some previous image encryption algorithms based on low dimensional space,all the encryption operations of CMCT-IEA are carried out in three-dimensional space,which makes the encryption results more complex and random.(2)An index-based simultaneous permutation-diffusion image encryption algorithm(ISPD-IEA)based on 2D-Price chaotic map is proposed.First,the classical Price function is improved to obtain a new two-dimensional Price map,and the chaotic sequence generated by the map is transformed into a chaotic matrix.Then,the values of the chaotic matrix are enlarged,rounded,and then added and modulo with the pixels of the plain image to get a random pixel matrix.The simultaneous permutation-diffusion mechanism of ISPD-IEA has the ability to move pixels around in an image and simultaneously effect all pixels’ minor modifications,which has high security and encryption efficiency.(3)A bit-based double-loop shift image encryption algorithm based on memristor hyperchaos sine map(MHSM-IEA)is proposed.Firstly,a new two-dimensional memristor sine map is used to generate chaotic sequences and convert them into chaotic matrices with the same size as the plain image.After amplification and integer operation,the sequence values of the chaotic matrix are added and modulo operation with the plain image to obtain a new pixel matrix.Secondly,chaotic matrix is used to scramble the pixel matrix.Then,the pixel matrix obtained after permutation is diffused by bit-based double-loop displacement in the direction of column/row,and the pixel values of each column/row are XOR computed with the pixel values of the previous column/row.Finally,the cipher-image is obtained after two rounds of permutation-diffusion operation.MHSM-IEA combines pixel-level positions scrambling for bit-level double-cycle displacement diffusion to enrich the diversity of the encryption process and effectively ensure the information security of the image.Experimental simulation and security analysis results show that the three image encryption algorithms designed in this paper can effectively protect the information security of the image,with high practicability and security.