摘要：The Digital watermarking technology has become increasing popular in the protection digital copyright. However, in the practical application, the watermarking algorithms should be combined with a secure copyright protection protocol to solve the copyright protection problems completely. In this paper, a novel buyer-seller watermarking protocol is proposed for piracy tracing, in which a memoryless Watermark Certification Authority (WCA) can offer a number of watermarks for a buyer simultaneously, avoiding itself being involved in each digital transaction operated between the buyer and the seller. Besides, in order to guarantee the anonymity of the buyer, the WCA can provide the buyer with an encrypted digital certificate and have it submitted directly to the seller by the buyer. In addition, the proposed protocol also can resolve other problems, such as the customer right problem, the binding attack problem, the anonymity problem, the conspiracy problem, the dispute problem. The analyses indicate that the proposed protocol is secure and practical.
