A content-protection scheme for multi-layered reselling structures

Abstract

Since the idea of digital watermarks was proposed, various watermarking schemes have been developed to protect digital contents in electronic transactions. However, most schemes limit themselves to the simplified buyer-seller model that can be applied to only a small number of cases rather than common scenarios in real life. In this paper, a more practical watermarking scheme is proposed to protect digital contents in real-world transactions using PKI (Public-Key Infrastructure). The proposed scheme is considered more practical in the sense that one or more reselling agents may exist between buyers and the original seller, and the seller can package the merchandise in advance without the involvement of buyers. The packaged merchandize can hence be made publicly accessible (e.g., on top of an open shelf) for the purpose of demonstration and circulates in the market. The proposed scheme also preserves the anonymity of the buyers while guaranteeing that the distributor of any illegal copy will be unambiguously identified. © 2004 by Springer Science+Business Media Dordrecht.