Research On Image Encryption Algorithm Based On Chaotic System

With the growing development of computer networks,multimedia dissemination of images and videos has become the mainstream method of information dissemination.In order to prevent malicious tampering,duplication,and deletion of information in images,image encryption has become the primary solution to this problem.Meanwhile,in order to ensure the "sensitive" information in images can be effectively transmitted in the open space,it is necessary for the sender and receiver to encrypt and decrypt the images.Therefore,image encryption technology has gradually become one of the research hotspots in the field of information security at home and abroad,and has received widespread attention.In order to improve the security of the image in the process of dissemination,this paper proposes an image encryption algorithm based on 2D-LSIM(2D Logistic-Sine Integrated Map)and an image visualization encryption algorithm based on the Chen hyper-chaotic system and DNA encoding.The specific innovations and work are as follows:(1)In order to improve the chaotic performance of one-dimensional chaotic map,a two-dimensional(2D)chaotic system 2D-LSIM based on Logistic map and Sine map is proposed.2D-LSIM is a chaotic system that generated by Logistic map and Sine map.Logistic map and Sine map through a combination of cascade,parallel and adder,and then expands the dimension from one dimension(1D)to 2D.Chaotic performance estimates indicate that 2D-LSIM has better ergodic properties,more complex chaotic behavior,and wider chaotic intervals than 2D-SLMM,2D-LSAM,and 2D-LSCM.(2)In order to improve the performance of the encryption algorithm,a new permutation-diffusion encryption algorithm is proposed,which combines 2D-LSIM to obtain a 2D-LSIM-based image encryption algorithm(LSIM-IEA).The initial state of2D-LSIM is generated by the secret key,and then the chaotic matrix generated by2D-LSIM is used for LSIM-IEA permutation and LSIM-IEA diffusion.LSIM-IEA permutation can effectively change the pixel position,LSIM-IEA diffusion can completely change the pixel value of the image,and diffuse small changes in the plain-image to the entire cipher-image.(3)Aiming at the problem that ordinary cipher-images are all textures and patterns,which are easy to be attacked by attackers,an image visualization encryption algorithm based on the Chen hyper-chaos system and DNA encoding is proposed.Firstly,saliency detection is used to extract important information in the plain-image,and an image block encryption algorithm based on the Chen hyper-chaos system and DNA encoding is used to pre-encrypt the important information.Secondly,the reference image is transformed by using discrete wavelet transform(DWT).Finally,the pre-encrypted image is combined with the reference image transformed image and the inverse discrete wavelet transform is performed to obtain a visually meaningful final cipher-image.