Multicast Security and Its Extension to a

Multicast is rapidly becoming an important mode of communication and a good platform for building group-oriented services. To be used for trusted communication , however, current multicast schemes must be supplemented by mechanisms for protecting traac, controlling participation, and restricting access of unauthorized users to data exchanged by the participants. In this paper, we consider fundamental security issues in building a trusted multicast facility. We discuss techniques for group-based data encryption, authentication of participants, and preventing unauthorized transmissions and receptions. We also describe the application of these principles and techniques in designing an architecture for secure multicast in a mobile environment. A multitude of presently emerging technologies will enable real-time information exchange among multiple participants. Low-cost, high-performance desktop video and audio processing equipment, such as cameras, coders, frame grabbers, and mixers, will make it economical to add real-time generation and display to general-purpose personal workstations. High-speed transmission and switching, now being deployed across the country, will enable instant dissemination of broad-band streams over a wide area. Powerful and exible multicast protocols, for dissemination of information to many recipients, will provide the glue that ties the broadband information generation and processing elements with the underlying broadband networks. A new generation of distributed applications will take advantage of these technologies and provide a quantum leap in network-based services. Multimedia tele-conferencing, computer-supported collaborative work, remote consultation and