Orthrus: Accelerating Multi-BFT Consensus through Concurrent Partial Ordering of Transactions (Extended Version)

TL;DR

Orthrus is a Multi-BFT consensus protocol that enhances transaction confirmation speed by employing partial ordering, significantly reducing latency while maintaining necessary global orderings for certain transactions.

Contribution

It introduces a novel partial ordering approach with an escrow mechanism to improve concurrency and reduce latency in Multi-BFT consensus systems.

Findings

Latency reduced by up to 87% in WAN environments.

Effective partitioning of transactions enhances concurrency.

Maintains consistency with a hybrid ordering approach.

Abstract

Multi-Byzantine Fault Tolerant (Multi-BFT) consensus allows multiple consensus instances to run in parallel, resolving the leader bottleneck problem inherent in classic BFT consensus. However, the global ordering of Multi-BFT consensus enforces a strict serialized sequence of transactions, imposing additional confirmation latency and also limiting concurrency. In this paper, we introduce Orthrus, a Multi-BFT protocol that accelerates transaction confirmation through partial ordering while reserving global ordering for transactions requiring stricter sequencing. To this end, Orthrus strategically partitions transactions to maximize concurrency and ensure consistency. Additionally, it incorporates an escrow mechanism to manage interactions between partially and globally ordered transactions. We evaluated Orthrus through extensive experiments in realistic settings, deploying 128 replicas in WAN and LAN environments. Our findings demonstrate latency reductions of up to 87% in WAN compared to existing Multi-BFT protocols.