Ian Brown, Colin Perkins and Jon Crowcroft
Proceedings of the 1st International Workshop on Networked Group Communication, Pisa, Italy, November 1999.
We outline a scheme by which encrypted multicast audiovisual data may be watermarked by lightweight active network components in the multicast tree. Every recipient receives a slightly different version of the marked data, allowing those who illegally re-sell that data to be traced. Groups of cheating users or multicast routers can also be traced. There is a relationship between the requirements for the scheme proposed here, the requirements for reliable multicast protocols, and proposed mechanisms to support layered delivery of streamed media in the Internet.