Summary: Scaling Secure Group Communication Systems: Beyond Peer­to­Peer
Yair Amir  Cristina Nita­Rotaru  Jonathan Stanton y Gene Tsudik z
Abstract
This paper develops several integrated security architecture scenarios for client­server group communication systems.
In an integrated architecture, security services are implemented in servers, in contrast to a layered architecture where the
same services are implemented in clients. We discuss benefits and drawbacks of each proposed architecture and present
experimental results that demonstrate the superior scalability of an integrated architecture.
Keywords: secure group communication, contributory group key agreement, peer groups, group communica­
tion, system architecture.
1 Introduction
Many routine activities in modern, everyday life involve the Internet: shopping for goods (such as books,
cars, software and even groceries), administering bank or credit card accounts and making financial transfers,
participating in voice or video­conferences, or simply playing games. Most such activities are in fact supported by
collaborative applications running over an integrated software platform, namely, a group communication system.
Group communication systems (GCSs) are essentially application­level multicast techniques providing reliable
and ordered message delivery, as well as a group membership service. GCSs have been built around a number of
different architectural models, such as peer­to­peer libraries, 2­ or 3­level middleware hierarchies, modular pro­
tocol stacks, and client­server. Prior research on such systems has tended to favor a client­server or a hierarchical
model. (Such models provide good scalability while maintaining a simple programming paradigm and traditional
group semantics.) However, security research for GCSs has focused mainly on peer­to­peer, or abstract group

Source: Amir, Yair - Department of Computer Science, Johns Hopkins University

Collections: Computer Technologies and Information Sciences