An enhanced buyer seller watermarking protocol

Digital watermarks are helpful about the possession identification as well as copyright and intellectual property protection for tons and tons of multimedia data transmitted through the Internet. In a buyer-seller watermarking protocol, both seller and buyer have to insert their watermarks into a copy. If unauthorized parties have drifted into market, the watermark detection and extraction algorithm will both identify exactly who has the legal ownership of that copy and trace back to the illegal reseller. In Memon and Wong´s protocol, the seller is responsible for watermarks insertion, but she/he has no idea what the buyer´s watermark is. As a result, the seller has no way to forge the buyer´s watermark. However, the seller doesn´t have to use her/his own private information in the watermark insertion process. This may bring about the problem of man in the middle attack. Besides, in their protocol, if there is a dispute, a judge is a must. To improve those shortcomings, we shall propose a new scheme where the seller has to use her/his own private key to do the watermarking insertion job. In our scheme, everyone can be the judge if there is a quarrel over the copyright. This provides a simple and fair solution to the judgment of copy deterrence.