Research Of Image Encryption Algorithm Based On Chaotic Mapping And S-box

With the rapid development of computer technology and network technology,the application of the Internet has been rapidly developed,a variety of application technologies emerge in an endless stream,so that people can understand more and broader information without leaving home,so information security issues caused wide attention and attention,especially the part of image security.In order to improve the security of information image,image encryption technology is particularly important.By studying the image encryption technology,chaos theory and s-box analysis,it is found that chaotic system has the advantages of sensitivity to initial conditions,ergodicity and random-like.As the core module of block cipher algorithm,s-box can be divided into static and dynamic.The static S box is constructed by mathematical method,the structure is simple,and the displacement effect of the encrypted image can be realized.The dynamic S box is constructed by chaos theory,and the ideal dynamic S box can be generated.Whether static or dynamic,their security is good,dynamic relative security,but the speed of encryption and decryption is a bit slow,although static security is a bit worse than dynamic security,but it is also safe enough,encryption and decryption speed is very fast.This paper mainly studies the chaotic mapping and S-box image encryption algorithm.Basic to static existing S box,and puts forward a kind of image encryption based on Logistic mapping and static S box algorithm,but because of the static S box scrambling effect is limited,and encryption image after the replacement key space is small,vulnerable,and to meet the requirements of every field of encryption,an improved algorithm,based on Logistic mapping and chaos dynamic S box of image encryption algorithm,the two algorithms are used in image encryption,the contrast effect of types of Encryption Major Research Contents:Algorithm 1,Image Encryption Algorithm Logistic mapping and static S box;Algorithm 2:image encryption algorithm based on Logistic mapping and chaotic dynamic s-box.Through a series of analysis of two different encrypted images,it is found that dynamic S can expand the key space of the encryption algorithm.The key space of dynamic S box is slightly larger than that of static S box,but the encryption and decryption speed of static S box is slightly faster.