Multiple-image Encryption Algorithm Based On DNA Encoding

In the era of big data,the Internet of everything will become the mainstream of the times.The transmission of all kinds of massive information through the network has put forward higher requirements on the security and efficiency of network transmission information.Efficient and secure digital image encryption algorithms need to be proposed to protect the privacy and security of individuals,society and even the nation.The biological properties of Deoxyribonucleic Acid（DNA）make it effective in improving the performance of encryption algorithms.Meanwhile,chaos theory occupies an essential place in cryptography.Therefore,DNA fast encoding is designed to improve the speed of DNA encoding.And based on this,two multi-image encryption algorithms are proposed to improve the performance of multi-image encryption algorithms.The main research is as follows.（1）A fast DNA encoding algorithm inspired by the Simultaneous Peripheral Operations On-Line system is proposed.Firstly,the base combinations corresponding to 256 different pixel values are pre-calculated and pre-stored in the computer memory or hard disk before DNA encoding and decoding operations.Secondly,the data are directly called from the base combination matrix when the corresponding DNA encoding or decoding operations are performed,thus avoiding a large number of repeated calculations.Finally,the final encoding and decoding results are obtained by adjusting the size of the generation matrix.Experimental analysis shows that for an image with the size of 2048×2048,the encryption time can be improved from 1.2397seconds to 0.1289 seconds by sacrificing 16KB of disk space.Therefore,the algorithm can significantly improve the speed of DNA encoding and decoding,which will promote the promotion and application of DNA computing in the field of image encryption to a certain extent.（2）A multiple-image encryption algorithm based on the genetic center dogma is proposed.Firstly,the k plain images are converted into binary format and resized to a three-dimensional matrix.Secondly,the images are scrambled on the bit plane by rotation of the bit plane and permutation between the bit planes.Thirdly,the result of the scrambling is DNA encoded,and the diffusion operation is realized by imitating the genetic center dogma and introducing RNA mutation.Finally,the final encrypted images are obtained by RNA decoding.The experimental analysis shows that the size of the key space can reach 2⁵³⁶,and the encryption time of the image with the size of512×512 is controlled within 0.9 seconds.The proposed algorithm is robust enough to resist common attacks such as differential attack,cropping attack,noise attack and selective plaintext attack.（3）A multiple-image encryption algorithm based on DNA convolution is proposed.Firstly,the designed one-dimensional exponential sine logistic map is used to generate the corresponding chaotic sequences.Secondly,the fast DNA encoding is performed on multiple plain images.Thirdly,the chaotic sequences are used to scramble multiple DNA-encoded images simultaneously.Besides,the designed DNA convolution is used to realize the image diffusion in combination with multiple DNA operations.Finally,the final encrypted images are obtained by fast DNA decoding.Experimental analysis shows that the size of the key space can reach 2⁴⁴²,the information entropy of the encrypted image can reach 7.9998.It takes only 0.7455 seconds to encrypt 4 images with the size of 256×256,and the algorithm has strong resistance to most common attacks.There are 185 figures,32 tables and 103 references in this thesis.