Study On Key Techniques Of Chaotic Image Encryption Based On Scramble-diffusion Structure

Chaotic cryptography is a hot research direction in the field of information security and mathematics.As a kind of nonlinear theory,chaos theory has the characteristics of sensitivity of initial value,pseudo-randomness and unpredictability,which is very suitable for the needs of cryptography research.At present,the algorithm design of chaotic cryptography still uses the size sorting of chaotic sequence as the main method of scrambling process.Because some scrambling methods designed by chaotic system have periodicity,the problem of periodic image scrambling and restoration will appear.In this paper,a chaotic image encryption scheme based on DNA coding of arithmetic sequence model is constructed based on scrambled diffusion structure and various mathematical theory methods.Then,on this basis,a 3D spatial cyclic displacement operation is proposed.Both algorithms realize a round of scrambling to change the position information of all pixels,which effectively avoids the problem of periodic restoration of the scrambling method.By studying the characteristics of scrambling diffusion structure and combining chaotic image encryption with other methods,a more secure image scrambling method and encryption algorithm are proposed.This paper mainly includes:(1)This paper presents an image encryption algorithm based on arithmetic sequence scrambling model and DNA coding.Based on the arithmetic sequence scrambling model and DNA coding image encryption algorithm,by combining arithmetic sequence principle and cyclic displacement theory,a arithmetic ring element extraction method is designed.In the process of element extraction and recombination,all pixels are scrambled in one round.By setting different tolerances of the different layer element scrambling,pixel position changes within the sub-block by control arithmetic progression scrambling model,chaos method to control each sub-block position change,due to the scrambling algorithm by two layers of transformation,so the attacker can get the right by attack the original image information,so as to improve the security of the algorithm.(2)Based on the arithmetic sequence scrambling model,a spatial transformation model of cyclic displacement operation is proposed.The spatial cyclic displacement model has excellent applicability in image encryption.In this paper,a two-dimensional cyclic displacement model is designed and improved,and an image scrambling method based on 3D cyclic displacement operation is proposed.3D cyclic displacement model can achieve completely different scrambling results through different parameter Settings.Combined with the spatial cyclic displacement scrambling method,this paper constructs a chaotic image encryption algorithm based on fractional wavelet transform and 3D cyclic displacement operation.(3)After a thorough study of chaotic systems,a new class of chaotic maps is proposed in this paper.Based on the cyclic periodic structure of cosine function,a one-dimensional cosine chaotic map(C-LS)is constructed.Combined with the rules of matrix operation,the cyclic information wave like Doppler wave is constructed.Based on the characteristics of cyclic information wave,a chaotic image synchronization scrambling diffusion encryption scheme is designed to realize the image synchronization scrambling diffusion.After the one-dimensional cosine chaotic map is constructed,a new spatio-temporal chaotic model is constructed,and a two-parameter dynamic coupling coefficient non-adjacent coupled lattice map is proposed.On this basis,a new encryption system based on TPDCCNCML and improved Hilbert fractal matrix model is constructed in this paper.Through the analysis of KS entropy,bifurcation graph,information entropy and MI,the experiment proves the superiority of TPDCCNCML,and the experiment proves the security of the encryption algorithm based on TPDCCNCML system.(4)In view of the high complexity of traditional image coding in encryption and the weak correlation of key image,this paper introduces quantum theory to optimize the key generation algorithm.Based on quantum key distribution protocol,a key generation scheme based on cyclic alignment is proposed in this paper.On this basis,a chaotic image encryption scheme based on BB84 quantum protocol is designed and implemented.Through the above research,it is found that the quantum-encoded image has better operability in the scramble-diffusion method,so this paper proposes a chaotic image encryption method based on the quantum encoding model.Through different quantum coding models,the original image pixels are represented as quantum entangled states,which can be directly rotated and scrambled by quantum transformation.On this basis,this paper proposes a quantum image chaotic encryption method based on fractional wavelet transform and iterative M4 matrix diffusion model.In this dissertation,it is verified that the effectiveness of the above chaotic image encryption algorithms through experimental verification and comparative analysis,respectively,and proved that all these algorithms have the advantages of large key space and sharp key sensitivity,and can effectively resist kinds of attacks.