A quantum steganography scheme using quantum wavelet transforms

Quantum steganography is a technology which can hide information effectively for achieving copyright protection. In this paper, a quantum steganography scheme using quantum wavelet transform and the novel enhanced quantum representation for quantum image is proposed, and this scheme can embed the secret text of size [Formula: see text] into a [Formula: see text] gray-scale carrier image. In the scrambling operation, the text is scrambled by the scrambling circuit including bit-reverse, quantum equal and CNOT gate to improve its security. Before embedding, the carrier image is first transformed by 1-level quantum Haar wavelet transform, and then its low-frequency part is divided into blocks. The simulation results suggest that the proposed scheme has good performance in visual quality and robustness. Finally, through the analysis of circuit complexity, the scheme has low complexity O(n).