A Quantum Watermark Protocol

Quantum watermarking is the technique which embeds the invisible quantum signal such as the owner's identification into quantum multimedia data (such as audio, video and image) for copyright protection. In this paper, a watermark strategy for quantum images is proposed based on flexible representation for quantum images (FRQI). Compared with the former strategy, which can only be used to verify the identity of the true owner of a carrier image, the proposed method can be used to find out who is