Cryptanalysis of an Image Encryption Using 2D Henon-Sine Map and DNA Approach

Recently, a novel gray image encryption scheme was proposed based on 2D Henon-Sine map (2D-HSM) and DNA approach. In the original scheme, the image pixels are substituted and diffused by the DNA approach and then permutated by a 2D-HSM key sequence. The structure of the encryption scheme is equivalent to substitution-diffusion-permutation. However, it is found that the attacker can recover the encrypted image by using the chosen plaintext attack without the secret keys. First, the equivalent key matrix used for permutation of the encryption scheme can be obtained, and the effects of diffusion can also be eliminated by the proposed method. Then, the mapping matrix between the input plaintext image and the intermediate image encrypted by the DNA approach is obtained. Both theoretical analysis and the experimental results show that the encrypted images using the original scheme can be cracked successfully. The attack complexity of our scheme is O(18), which greatly reduces the number of attacks compared with the traditional method. In addition, our approach will help to improve the security of image-encryption schemes based on permutation-diffusion-scrambling structures.