An Enhanced Watermarking Protocol for Electronic Copyright Management

In Piva et al\´s watermarking scheme for electronic copyright management system (ECMS), authors were considered trusted potentially, so a dishonest author could authorize more than one distributor to sell her one document, named "One Document to Multi-distributor" problem, which would damage the benefit of the distributors. To resolve the problem, in this paper, we propose an enhanced watermarking protocol based on Piva et al\´s scheme by introducing document nature code (DNC) and register records table. In addition, our protocol offers the distributor an efficient means to verify his right to an authorized digital document