Secure Group Communication in Asynchronous Networks with Failures: Integration and Experiments

Increasing popularity and diversity of collaborative applications prompts the need for highly secure and reliable communication platforms for dynamic peer groups. Security mechanisms for such groups tend to be both expensive and complex and their integration with reliable group communication services presents a formidable challenge. This paper discusses some important integration issues, reports on the implementation experience and provides experimental results. Our approach utilizes distributed group key management developed by the Cliques project. We enhance it to handle processor and network faults (under a fail-stop or crash-and-recover model) and asynchronous membership events (such as cascading joins, leaves, merges and network partitions). Our approach leverages the strong properties provided by the Spread group communication system, such as message ordering, clean failure semantics and a membership service. The result of this work is a secure group communications layer and an API which provide the application programmer both standard group services as well as flexible security services.