Abstract
Information hiding aims to embed secret data into the multimedia, such as image, audio, video, and text. In this paper, two new quantum information hiding approaches are put forward. A quantum steganography approach is proposed to hide a quantum secret image into a quantum cover image. The quantum secret image is encrypted first using a controlled-NOT gate to demonstrate the security of the embedded data. The encrypted secret image is embedded into the quantum cover image using the two most and least significant qubits. In addition, a quantum image watermarking approach is presented to hide a quantum watermark gray image into a quantum carrier image. The quantum watermark image, which is scrambled by utilizing Arnold's cat map, is then embedded into the quantum carrier image using the two least and most significant qubits. Only the watermarked image and the key are sufficient to extract the embedded quantum watermark image. The proposed novelty has been illustrated using a scenario of sharing medical imagery between two remote hospitals. The simulation and analysis demonstrate that the two newly proposed approaches have excellent visual quality and high embedding capacity and security.