Research On The Application Of Double Scrambling And DNA Coding Dynamic Update Algorithm In Chaotic Image Encryptio

The rapid development of communication technology has made it possible for various forms of data,such as text and images,to be transmitted more frequently and rapidly over networks.However,due to the openness and sharing nature of networks,the security of information transmission is severely threatened.As an important information carrier,digital image is easy to be the target of attack because of its characteristics of high redundancy,direct information transmission and large data volume.The security of text images is very important to the field of image processing and information.With the development of chaos theory,image encryption algorithms based on chaos have shown good ability to protect image data.Deoxyribonucleic Acid(DNA)sequence has the advantages of massive parallelism,huge storage and ultra-low power consumption.A secure and efficient image encryption algorithm can be designed by combining chaos and encryption theory.The implementation of image encryption,decryption and security testing based on Graphical User Interface(GUI)can improve its practical application value,so as to better protect the privacy and security of image data.The main work is as follows:(1)A closed-loop dynamic updating algorithm of double permutation-DNA rows and columns based on two dimensional cascade modulated coupled chaotic system(2DLICM)was proposed.In the scrambling stage,in order to overcome the shortcomings of the Hilbert curve adjacent storage and improve the scrambling efficiency,a new pixel reconstruction method is proposed by combining the Hilbert curve with the improved Knuth-Durstenfeld shuffling algorithm.In the diffusion phase,using the parallel computing power and high storage density of DNA coding,a two-round diffusion of DNA coding was proposed.When the last line of ciphertext was generated,the first line of ciphertext was updated to realize the closed-loop dynamic update of the encryption system.The experimental results and security analysis show that the designed algorithm can effectively improve the efficiency of information transmission.(2)A chaotic block image encryption algorithm based on intra-block and inter-block double scrambling and DNA dynamic coding was proposed.The chaotic sequences generated by Chen chaotic system and 2D-LICM chaotic system were used to perform improved intra-block shuffling and inter-block index scrambling on image pixels.In the diffusion stage,in order to enhance the complexity and robustness of DNA encoding,two new DNA algebraic operators,namely left clockwise shift operator and right clockwise shift operator,are defined.The chaotic sequence is used to dynamically select DNA encoding rules,operation rules and decoding rules,which makes the encryption process have good randomness and operability.Experimental results show that the algorithm can resist noise attack and cropping attack to a high degree.(3)Based on the above designed two kinds of chaos and DNA encoding image encryption algorithm,MATLAB image User Interface(GUI)is used to realize,so as to increase the practicability and user friendliness of the system.Through the system interface,users can more conveniently and quickly encrypt,decrypt and test images.At the same time,users can also choose a more suitable encryption algorithm according to different application scenarios,so that the system has higher flexibility in different occasions.