Source authentication in group communication

Multicast is a relatively new and emerging communication mode in which a sender sends a message to a group of recipients in just one connection establishment... reducing broadband overhead and increasing resource utilization in the already congested and contented network... The focus of the research in this area has been in two directions: first, building an efficient routing infrastructure, and secondly, building a sophisticated security infrastructure. The focus of this work is on the second issue. An ideal authenticated multicast environment ... provides authenticity for all the communication operations in the system... We ... propose a comprehensive solution to the problem ... for all its possible operations... 1. one-to-one (or joining mode) 2. one-to-many (or broadcast mode) 3. many-to-one (or concast mode) 4. intermediate (or transit mode) ... We study the ... mode known as anycast, in which a server is selected from a group of servers. Further we develop ... schemes for group-based communication exploiting the distinct features of one-time signatures... cover situations when a threshold number of participants are involved and ... where a proxy signer is required.