Image encryption scheme based on double permutation and DNA

This paper mainly contributes a bit-level and pixel-level double-permutation image encryption scheme based on DNA coding technology, which can effectively solve the problem that adjacent pixels in an image are difficult to be completely disordered. Firstly, the Hamming distance between image pixel and a value at the same position in a chaotic sequence is calculated and the result is used to be the cyclic shift distance of the pixel to achieve bit-level permutation; secondly, the modified Z curve is used for the first global permutation process, and the image is further permutated by the method of block restructuring to compensate for the shortage of modified Z curve permutation; thirdly, pixel pairs are selected and the pixel pairs are used as information and control positions respectively to DNA encode the image by dynamically selecting the DNA encoding rules, and then diffusing the encoded image following the rules of DNA base manipulation; finally, the diffused image is decoded to complete the image encryption process. We perform simulation experiments on the image encryption algorithm and analyze its security performance, and we could get the conclusion that the encryption algorithm can encrypt images quickly and effectively, the obtained cipher images are highly resistant to noise attacks, cropping attacks, and different attacks, meanwhile, the cipher images have a lower correlation between pixels.