Bridging Paxos and Blockchain Consensus

The distributed consensus problem has been extensively studied in the last four decades as an important problem in distributed systems. Recent advances in decentralized consensus and blockchain technology, however, arose from a disparate model and gave rise to disjoint knowledge-base and techniques than those in the classical consensus research. In this paper we make a case for bridging these two seemingly disparate approaches in order to help transfer the lessons learned from the classical distributed consensus world to the blockchain world and vice versa. To this end, we draw parallels between blockchain consensus and a classical consensus protocol, Paxos. We also survey prominent approaches to improving the throughput and providing instant irreversibility to blockchain consensus and show analogies to the techniques from classical consensus protocols. Finally, inspired by the central role formal methods played in the success of classical consensus research, we suggest more extensive use of formal methods in modeling the blockchains and smartcontracts.