Secure group communication: a dynamic approach

摘要

Key distribution is a major cryptographic component for secure communication. To ensure privacy data must be encrypted with keys which are distributed securely. The keys must be properly authenticated. Most of the research on key distribution has focussed on two-party systems although there is some notable work on conference systems (with more than two parties). However the dynamic aspect of such systems has been neglected. In this paper we address this issue and consider a scenario appropriate for internet applications. We show how a conference system can be extended efficiently to enable new participants to join, in such a way that all earlier communication within the conference is protected. We also consider the case when participants leave a conference. Our approach is general and can be used with any conference system. The security of our dynamic extension is essentially the same as that of the conference system. Finall we discuss several threats to dynamic conferencing.