James A. Cowling Daniel S. Myers Barbara Liskov Rodrigo Rodrigues Liuba Shrira HQ Replication: A Hybrid Quorum Protocol for Byzantine Fault Tolerance. 177-190 2006 conf/osdi/2006 OSDI http://www.usenix.org/events/osdi06/tech/cowling.html db/conf/osdi/osdi2006.html#CowlingMLRS06