The Rampart toolkit for building high-integrity services

Rampart is a toolkit of protocols to facilitate the development of high-integrity services, i.e., distributed services that retain their availability and correctness despite the malicious penetration of some component servers by an attacker. At the core of Rampart are new protocols that solve several basic problems in distributed computing, including asynchronous group membership, reliable multicast (Byzantine agreement), and atomic multicast. Using these protocols, Rampart supports the development of high-integrity services via. the technique of state machine replication, and also extends this technique with a new approach to server output voting. In this paper we give a brief overview of Rampart, focusing primarily on its protocol architecture. We also sketch its performance in our prototype implementation and ongoing work.