Steward: Scaling Byzantine Replication to Wide-Area Networks
Steward is a hierarchical Byzantine fault-tolerant replication system developed as part of DARPA's Self-Regenerative Systems project. The system is suited to deployments consisting of multiple wide-area sites, each with a cluster of replication servers. Steward continues to work correctly even if some of the replication servers in each site are compromised and act in an arbitrary manner.
Steward deploys a hierarchical architecture. Each site runs local Byzantine fault-tolerant protocols to confine the effects of malicious replias to their local site. Thus, each site acts as a trusted logical unit. A benign fault-tolerant replication protocol runs among the logical units over the wide-area network.
Our work on Steward was partially funded by the Defense Advanced Research Project Agency (contract FA8750-04-2-0232), and by the National Science Foundation (grants 0430271 and 0430276).
Steward was fully implemented and underwent a Red Team evaluation in December 2005. The code was written in C and runs on Linux.
LicenseSteward may be freely used and distributed under some conditions. Please review the license agreement for more details.
DownloadSource code can be downloaded here.