Lightweight Secure Group Communication

An advantage of today’s high speed networks is the ability to support group communication. Applications that support group communication allow the free exchange of ideas and data in real time, regardless of the physical distance between the participants. Unfortunately, support for additional protocol features such as reliability, secrecy, and total ordering in the multicast context requires more bandwidth and greater complexity than in traditional point-to-point communication. In this paper we describe a middleware software layer and associated API that attempts to minimize these requirements by providing multiple secure channels based on IP multicast within the same logical group. Named LSGC (lightweight secure group communication), the software provides the important features needed by a group application: reliable delivery, best-effort delivery, and security. In providing both reliable and unreliable channels, an application need pay only for the delivery assurances it needs. We conclude with a description of our implementation and supporting performance data.