Imitater: An Efficient Shared Mempool Protocol with Application to Byzantine Fault Tolerance

TL;DR

Imitater introduces an efficient shared mempool protocol for BFT consensus that enhances throughput and latency, especially under network instability and malicious conditions, by chaining microblocks and applying coding techniques.

Contribution

The paper presents Imitater, a novel shared mempool protocol that can be integrated into BFT protocols to improve efficiency, totality, and availability while preserving transaction order.

Findings

Imitater-HS outperforms Stratus-HS in throughput and latency.

Efficiency gains increase with more faulty nodes.

Validated in a 256-node system.

Abstract

Byzantine Fault Tolerant (BFT) consensus, a cornerstone of blockchain technology, has seen significant advancements. While existing BFT protocols ensure security guarantees, they often suffer from efficiency challenges, particularly under conditions of network instability or malicious exploitation of system mechanisms. We propose a novel Shared Mempool (SMP) protocol, named Imitater, which can be seamlessly integrated into BFT protocols. By chaining microblocks and applying coding techniques, Imitater efficiently achieves \emph{totality} and \emph{availability}. Furthermore, a BFT protocol augmented with Imitater ensures \emph{order preservation} of client transactions while mitigating the risks of \emph{over-distribution} and \emph{unbalanced workload}. In the experiment, we integrate Imitater into the HotStuff protocol, resulting in Imitater-HS. The performance of Imitater-HS is validated in a system with up to 256 nodes. Experimental results demonstrate the efficiency of our approach: Imitater-HS achieves higher throughput and lower latency in the presence of faulty nodes compared to Stratus-HS, the state-of-the-art protocol. Notably, the throughput improvement increases with the number of faulty nodes.