Multimedia security in group communications: recent progress in key management,authentication, and watermarking

Multicast is an internetwork service that provides efficient delivery of data from a source to multiple receivers. It reduces the bandwidth requirements of the network and the computational overhead of the host devices. This makes multicast an ideal technology for communication among a large group of participants. Secure group communications involves many service types include teleconferencing, pay TV and real-time delivery of stock quotes. IP multicast is the traditional mechanism to support multicast communications. Multicast security includes group membership control, secure key distribution, secure data transfer and copyright protection. This paper is an overview of the schemes proposed for group key management, authentication and watermarking in wired networks with fixed members and wireless networks with mobile members.A preliminary version of this paper was presented at the IASTED International Conference on Communications and Computer Networks, Cambridge, MA 4-6 November 2002.