The architecture and performance of security protocols in the ensemble group communication system

Abstract

Ensemble is a Group Communication System built at Cornell and the Hebrew universities. It allows processes to create process groups within which scalable reliable fifo-ordered multicast and point-to-point communication are supported. The system also supports other communication properties, such as causal and total multicast ordering, flow control, etc.This paper describes the security protocols and infrastructure of Ensemble. Applications using Ensemble with the extensions described here benefit from strong security properties. Under the assumption that trusted processes will not be corrupted, all communication is secured from tampering by outsiders.Our work extends previous work performed in the Horus system (Ensemble's predecessor) by adding support for multiple partitions, efficient rekeying, and application defined security policies. Unlike Horus, which used its own security infrastructure with non-standard key distribution and timing services, Ensemble's security mechanism is based on off-the shelf authentication systems, such as PGP and Kerberos.We extend previous results on group rekeying, with a novel protocol that makes use of diamond-like data structures. Our Diamond protocol allows the removal of untrusted members within milliseconds.

iSAN – An Intelligent Storage Area Network Architecture

“…First, it is a well engineered GCS toolkit with a number of of unique functionalities such as support for composable protocol stacks. Secondly, Ensemble has a powerful, provably correct, multicast aware security infrastructure [19]. Besides, Ensemble is event driven and is considered to be superior to thread based systems like Horus .…”

Temporal Verification in Secure Group Communication System Design

“…The Ensemble system [9] adds one security layer on top of former ISIS and HORUS group communication systems. Ensemble efficiently computes group keys, offers several security policies at the application level, and supports multiple partitioning.…”

Working Towards Strong Wireless Group Communications: The Janus Architecture

“…formal verification. Current projects such as InterGroup [2], Spinglass and Ensemble [14] are exploring the issues of scalability and security in group communications.…”