Participants Registration, Validation, and Key Distribution for Mbone Conferencing

There are several tools available that can be used to hold multimedia conference sessions within the Internet Multicast Backbone (MBone). Most of these tools provide means for public and private conferencing, but ooer no possibility to register participants of particular conference sessions, or to authenticate them accordingly. In a private conference session, every message is encrypted with a session key and this key must be distributed out-of-band, e.g. by using Privacy Enhanced Mail (PEM) or Pretty Good Privacy (PGP) messages. DiRK (Distributed Registration and Key distribution) is a technique that can be used in a conferencing system, such as the MBone, to handle participants registration and key distribution in a decentralized and fully distributed way. This paper overviews the basic principles of DiRK, and mainly focuses on a prototype implementation of DiRK in a session registration tool (srt) for the MBone.