A practical and secure buyer-seller watermarking protocol

Digital watermarking is an emerging technology for combating copyright piracy. In real applications, the transaction between a buyer and a seller is done through a specific watermarking protocol, which enables the seller to successfully identify a traitor from a pirated copy, while preventing the dishonest seller from framing an inno cent buyer. In this paper, we propose a new buyer-seller watermarking protocol. Compared to the previous works, it makes two improvements, which make it more practi cal. First, no third party is introduced and hence, the problem of the seller (or buyer) colludes with a third party to cheat the buyer (or seller) is solved. Second,a double watermark insertion is avoided, and then the final quality of the watermarked content is higher and the result of the watermark detection is more accurate.