Three-level quantum image encryption based on Arnold transform and logistic map

Quantum computation improves the efficiency and security of cryptography by utilizing characteristics of quantum mechanics. In this paper, a novel three-level quantum image encryption algorithm based on Arnold transform and logistic map is proposed. To obtain satisfactory encryption results, three-level encryption procedures including block-level permutation, bit-level permutation and pixel-level diffusion are performed on the original image. First, the classical plaintext image is transformed into quantum form with novel enhanced quantum representation model. Then, quantum Arnold transform (QArT) is used to scramble the image sub-blocks by processing the qubits that denote position information. By iterating block-level permutation procedure with different block-size and different parameter of QArT, the period defect of QArT can be made up to some extent. Next the bit-level permutation is performed by scrambling the bit-plane order according to a sequence generated with logistic map. Finally, the ciphertext image can be obtained by performing bit-level diffusion through XOR operation between bit-level permutated image and a pseudo-random sequence acquired from logistic map. The corresponding quantum circuits realization are given, and simulations results show that the proposed three-level quantum image encryption scheme has high level of security and outperforms its classical counterpart in terms of efficiency.