A parallel double scrambling encryption scheme for MQIR image based on random combination

With the rapid expansion of quantum information and quantum networks, quantum image security research has gradually become a research hotspot in the field of information security. However, in the field of quantum image processing, most encryption algorithms are independent of color components or position space, and the encryption effect is not satisfactory. Therefore, we propose a parallel double scrambling encryption scheme for a multimode quantum image representation (MQIR) image based on random combination, which uses the principle of random combination to encrypt the position and pixel value of the image at the same time, so as to realize the parallel double scrambling of the pixel value and position of the MQIR image. The algorithm is based on specific keys when encrypting, so that the generation of the keys are related to the seeds. At the same time, a certain number of bits are selected on the qubits representing the three-dimensional positions, and NOT gates are added. This is so that the generated pseudo-random sequence is also related to the number of qubits chosen for the three-dimensional position of the quantum image, making it more difficult to decrypt the encrypted image. We give the quantum circuits with parallel double scrambling and inverse scrambling for MQIR quantum images. In the circuit, we divide the image into four sub-blocks and locate them respectively at the end of each sub-block. The encryption key for different sub-blocks depends on the selected seed. This circuit only needs to encrypt four times without iterating. The algorithm is simple and has a large key space. Finally, we perform the correlation coefficient (CC) and the number of pixels change rate (NPCR) analysis between the plaintext image and the encrypted image. The experimental results show that the CC exhibits low correlation between the plaintext image and the encrypted image, and the NPCR between them is extremely high, which verifies the effectiveness and security of the proposed quantum image encryption scheme. (c) 2022 Elsevier B.V. All rights reserved.