Research On Image Encryption Method Based On Chaos Mapping And DNA Computing

With the development of the Internet and big data,the research of image encryption has become one of the hot spots in the field of information security.As the expression form of information in contemporary multimedia,traditional image encryption technology is difficult to solve the problems of huge amount and high redundancy of digital image encryption.The image encryption method based on chaotic system is more suitable for image encryption because of its ergodicity,high sensitivity and pseudo-randomness.Based on the in-depth study of chaos theory and DNA coding theory,two image encryption methods based on chaotic system and DNA coding are designed in this paper:First,a digital image encryption technology based on chaotic system and dynamic DNA coding is proposed.By mapping index sequence to chaotic system to scramble the image pixels position matrix,the image matrix encoded with dynamic DNA is performed base operation with the given DNA sequence.Then,calculate the hash value of the given DNA sequence using Keccak as the initial value of the chaotic Chen system.According to the quaternary hyper chaotic sequences generated by the hyper-chaotic Chen system,base replace the DNA coding pixel value for a certain number of times.Finally,further enhance the confusion and diffusion characteristics of the algorithm by cipher-text feedback and chaotic system iteration.Secondly,an algorithm based on Joseph ergodic with variable step length and DNA dynamic coding is proposed.Firstly,the random sequence generated by chaotic mapping is taken as the variable step length of Joseph ergodic to scramble the pixels position,so the image encryption algorithm is performed.Secondly,on the security lack of DNA computing rules,dynamic selecting DNA coding rules and DNA coding image,perform base operation with given DNA sequence.Because the DNA coding rules of image pixels are dynamic,the hidden danger caused by the lack of DNA coding rules is well solved,and the security of the algorithm is improved.After that,the confusion and diffusion characteristics of the algorithm are improved by cipher-text feedback and chaotic system iteration.The test results show that the algorithm not only has large key space and strong sensitivity to key,but also can effectively resist attacks such as statistical analysis and exhaustive analysis.At the end of this paper,the content of the article is summarized,and the future research direction is prospected.