Brief announcement: Practical synchronous byzantine consensus

Abstract

This paper presents new protocols for Byzantine state machine replication and Byzantine agreement in the synchronous and authenticated setting. The PBFT state machine replication protocol tolerates f Byzantine faults in an asynchronous setting using n = 3f + 1 replicas. We improve the Byzantine fault tolerance to n = 2f +1 by utilizing the synchrony assumption. Our protocol also solves synchronous authenticated Byzantine agreement in fewer expected rounds than the best existing solution (Katz and Koo, 2006).