On the Core Mechanisms of Consensus Algorithms for Benign and Byzantine Faults (Preliminary Version)

Consensus is a fundamental and difficult problem in fault tolerant distributed computing, and numerous consensus algorithms have been published. The paper proposes a generic consensus algorithm that highlights, through well chosen parameters, the core mechanisms of a number of well-known consensus algorithms including Paxos, OneThirdRule, PBFT, FaB Paxos. Interestingly, the generic algorithm allowed us to identify a new Byzantine consensus algorithm that requires n > 4b, inbetween the requirement n > 5b of FaB Paxos and n > 3b of PBFT (b is the maximum number of Byzantine processes). The paper contributes to identify key similarities rather than non fundamental differences between consensus algorithms.