Antigone: Implementing Policy in Secure Group Communication

Significant strides have been made in achieving strong semantics and security guarantees within group communication and multicast systems. However, the scope of available security policies in these systems is often limited. In contrast, the applications that require the services provided by these sys-tems can differ significantly in their security policy needs. Often application designers have to either make significant compromises in using a given group communication system or build their own cus-tomized solutions, an error-prone task. This paper presents Antigone, a framework that provides a suite of mechanisms from which flexible application security policies may be implemented. With Antigone, developers may choose a policy that best addresses their security and performance requirements of an application requiring group communication. We describe the Antigone’s mechanisms, consisting of a set of micro-protocols, and show how different security policies can be implemented using those mech-anisms. We also present a performance study illustrating the security/performance tradeoffs that can be made using Antigone. Through an example conferencing application, we demonstrate the use of the Antigone applications programming interface and consider the use of policy in several distinct session environments.