Quantum image encryption based on Baker map and DNA circular shift operation

Quantum computation can improve the efficiency of image processing by utilizing parallelism and superposition characteristics. In this paper, a quantum cryptosystem based on Baker map and deoxyribonucleic acid (DNA) circular shift operation is designed. Firstly, the digital image to be encrypted is firstly represented with a novel enhanced quantum representation model. Then quantum Baker map is used to permutate the position information of the prepared quantum image. Next, the designed DNA circular shift operation is performed to preliminarily change the color information of the scrambled image. Finally, the ciphertext image is obtained by implementing the exclusive OR (XOR) operation between the pseudo-random sequence generated by a four-dimensional (4D) hyper-chaotic system and the DNA shift operated image. Numerical experimental results and security analysis verify that the proposed scheme has good performance at securing information storage and transmission as the histograms of ciphertexts are uniform, the correlation coefficient values of three directions are very close to 0, the average information entropy is 7.9972, the key space is more than 1015x4 to resist brute-force attack. Furthermore, it has lower computational complexity compared with classical algorithms.