A Group Membership Protocol for an Intrusion-Tolerant Group Communication System
HariGovind V. Ramasamy · 2002
Group Communication Systems have been developed to address the problem of maintaining consistency of replicated information. This thesis describes the research work that resulted in the design, development, and informal validation of a group membership protocol for an intrusion-tolerance group communication system (ITUA GCS). This group membership protocol provides consistent group membership to process groups in the presence of malicious faults resulting from intrusions. We describe the properties guaranteed by this group membership protocol, the assumptions under which the protocol functions, a detailed algorithmic description of the protocol, and an informal proof that the protocol satisfies the stated properties. The group membership protocol has been implemented as a layer in the ITUA GCS, which is a layered protocol stack. We also describe the protocol implementation details, the framework in which this layer was implemented, and the changes made to this framework in order to add the protocol. We then present performance results for the group membership protocol. The protocol was instrumented to provide detailed information about the cost incurred during fault-free operation and while tolerating both single and multiple correlated intrusions. The results are useful in that they provide new insights into the cost of providing intrusion-tolerant group communication, and suggest ways that this cost could be reduced in the future.