Least significant qubit algorithm for quantum images

Gaofeng Luo, Ri‐Gui Zhou, WenWen Hu +3 more

Shen Wang, Jianzhi Sang, Xianhua Song +1 more

J. Jennifer Ranjani

Gaofeng Luo, Ling Shi, Tongcheng Huang +1 more

Quantum image watermarking technology is influenced by embedding algorithm, which permanently distorts the embedded quantum carrier image.To protect and authenticate quantum images without damaging the carrier images, this study proposed a quantum image reversible watermarking algorithm combining the most significant qubit (MSQb) and the least significant qubit (LSQb).First, a binary watermark image, a grayscale carrier image, and an empty key image were represented using the novel enhanced quantum representation of digital images.Second, the encrypted qubit of the binary watermark image was matched with the MSQb of the carrier image.If they were equal, then the high qubit of the quantum key image was flipped.Otherwise, the encrypted qubit of the binary watermark image was matched with the XOR value of the lowest two qubits of the carrier image.The LSQb of the carrier image was modified according to the matching result.Finally, the quantum watermarked image was obtained.Simulation experiments and theoretical analysis verified the feasibility and watermark performance of the scheme.Results demonstrate that the scheme achieves correct extraction of quantum image watermark and lossless restoration of original image.The visual quality PSNR of the carrier image embedded with watermark through the scheme is improved by approximately 4% compared with that through the traditional LSQb method.The study provides a reference for studying and implementing reversible image watermarking technology in the era of quantum computer, which can be applied to harsh copyright protection and authentication of the visual quality of the original carrier image.

Zhiguo Qu, Zhenwen Cheng, Xiaojun Wang

Embedding secret information into quantum carrier image for covert communication is one of significant research fields of quantum secure communication. Using good imperceptibility and high embedding efficiency of matrix coding, this paper proposes a novel matrix coding-based quantum steganography algorithm for quantum color images. In order to better apply matrix coding in actual demand, two different embedding methods are proposed. One embedding method is single pixel-embedded (1, 3, 2) coding, called SPE (1, 3, 2) coding for short. This method embeds two qubits of secret information into three least significant qubits (LSQbs) of a single pixel of quantum carrier image, and at most only one LSQb would be changed. The other embedding method is the multiple pixels-embedded (1, 3, 2) coding, called MPsE (1, 3, 2) coding, in which three LSQbs of multiple carrier pixels are utilized to embed two secret qubits. On account of experimental simulation obtained in the MATLAB environment, it shows that the new algorithm has good performance in the imperceptibility, the security, the embedding efficiency, and the embedding capacity.

Fei Yan, Salvador Elías Venegas-Andraca, Kaoru Hirota