Copy protection for DVD video

The prospect of consumer digital versatile disk (DVD) recorders highlights the challenge of protecting copyrighted video content from piracy. We describe the copy-protection system currently under consideration for DVD. The copy-protection system broadly tries to prevent illicit copies from being made from either the analog or digital I/O channels of DVD recorders. An analog copy-protection system is utilized to protect the NTSC/PAL output channel by preventing copies to VHS. The digital transmission of content is protected by a robust encryption protocol between two communicating devices. Watermarking is used to encode copy-control information retrievable from both digital and analog signals. Hence, such embedded signals avoid the need for metadata to be carried in either the digital or analog domains. Finally, the copy-protection system provides the capability for one-generation copying. We discuss some proposed solutions and some of the implementation issues that are being addressed.