What Issues Play a Role in Designing an Effective System?

One of the most quoted applications for digital watermarking is in the context of copy-protection of digital (multi-)media. In its most basic form a watermark is used as a single bit that indicates whether or not content is copyrighted. By the nature of a watermark, this copy-protection bit is (theoretically) strongly tied to the content: it can only be removed when the content suffers serious degradation. As simple as this idea may seem, the actual design of an appropriate watermarking scheme and its application in a copy protection system is quite complicated. In this article we illustrate the various issues that play a role in designing a copy-protection system for digital versatile disk (DVD) video as perceived by Millennium, one of the two contenders in the DVD-video copy protection standardization activity. We present the Millennium watermark system, the systems proposed for DVD video copy protection by Philips, Macrovision, and Digimarc. We also address some specific system aspects, such as watermark detector location and copy generation control.