Albatross – An optimistic consensus algorithm

Distributed ledgers have the potential to revolutionize the financial landscape by removing trusted third parties. At the heart of most distributed ledgers is their consensus protocol. The consensus protocol describes the way participants in a distributed network interact with each other to obtain and agree on a shared state. While classical Byzantine fault tolerant (BFT) algorithms are designed to work in closed, size-limited networks only, modern distributed ledgers - and blockchains in particular - often focus on open, permissionless networks. In this paper, we present a novel blockchain consensus algorithm for open, permissionless networks, called Albatross, inspired by speculative BFT algorithms. We argue that the protocol is secure under regular PBFT security assumptions and has a theoretical performance close to the maximum for single-chain Proof-of-Stake consensus algorithms. We conclude by describing our future work related to Albatross.