Research On Double Chaotic Image Encryption Based On DNA Coding And Optimal Solution

In the process of information society,with the rapid development of network technology,information can be expressed in various ways,such as text,data,audio,images,video and characters,among which digital images and video are used as a mainstream information carrier in life,which are widely used in military,diplomatic,satellite communications and daily life.The security of information is not only related to personal privacy,corporate interests and financial security,but also to national security.In this era,it is urgently needed to protect the security of information.With the rapid development of nonlinear dynamics and chaos theory,the application of using chaos theory to encrypt multimedia data has become a new research hotspot.In view of the current development of digital images,digital image encryption has been researched and applied.In the basic knowledge of chaos theory and DNA coding,the paper analyzes the encryption technology in the field of digital image,and studies the encryption algorithm of DNA coding and hyperchaos,the optimal solution sequence and the double chaotic encryption of fractional Fourier transform.Both of these algorithms are applied to digital image encryption and encryption process.The main research work is as follows:(1)An color digital image encryption scheme based on DNA coding and hyperchaos is designed.Firstly,the image is layered,the DNA coding operation is carried out,and the randomness of the hyperchaotic sequence is used to dynamically determine the basic DNA coding rules and the DNA operation type.After the coded digital matrix is processed by block processing,the natural DNA matrix is generated by hyperchaos and the DNA matrix addition operation is dynamically selected.This property improves the randomness and complexity of the chaotic encryption process.After multiple rounds of encryption,it also makes full use of the limited coding types and operation types.(2)A double chaotic encryption scheme with optimal solution and Fourier transform is designed.The scheme is firstly subjected to discrete cosine transform operation,and then the improved Henon map and fractional Fourier transform are used to obtain the optimization algorithm.Logistic chaos is integrated.The plain image pixels are selected to solve the optimal solution sequence,and the encryption is performed according to the order of the optimal solution sequence to get the final ciphertext image.The simulation results show that the improved optimal solution algorithm achieves better encryption effect,which is not only sensitive,but also has a large key space and can effectively resist attacks.The structure of the article is as follows: The first chapter is the introduction,which mainly summarizes the status quo at home and abroad and the core content of this thesis.The second chapter introduces the basic knowledge of chaotic system theory.The third chapter is the encryption of hyperchaotic color images based on DNA sequences.The fourth chapter is the double chaotic image encryption based on the optimal solution and two-dimensional discrete fractional Fourier transform.The fifth chapter is the conclusion and prospect of this thesis,introduce the unsolvable problems encountered in the research of the thesis and the factors that have not beenconsidered,and the areas that need to be improved in the future.