On Secure and Anonymous Buyer-Seller Watermarking Protocol

Buyer-seller watermarking protocols incorporate digital watermarking with cryptography, in order to protect digital copyrights and privacy rights for the seller and the buyer before, during, and after purchase activities in e-commerce. In this paper, we analyze the security of some previously proposed protocols, and propose a secure and anonymous buyer-seller watermarking protocol. In contrast to early work, our improvement on the protocol´s security properties ensures that the design requirements are fulfilled. The proposed protocol is able to simultaneously solve the piracy tracing problem, the customer´s rights problem, the unbinding problem, the anonymity problem, the conspiracy problem, and the dispute problem. In the proposed protocol, a buyer can purchase digital contents anonymously but his anonymity can be revoked as soon as he is adjudicated to be guilty by a legal institute, such as civil court.