Practical Byzantine Reliable Broadcast on Partially Connected Networks (Extended version)

TL;DR

This paper enhances Byzantine reliable broadcast protocols on partially connected networks by introducing layer-specific and cross-layer optimizations, significantly reducing communication overhead and latency in practical simulations.

Contribution

It demonstrates how to optimize existing protocols combining Bracha's and Dolev's algorithms for better efficiency in partially connected networks.

Findings

Optimizations reduce total transmitted information by 25%.

Protocol latency decreases by 50% in simulations.

Effective combination of layer-specific and cross-layer techniques.

Abstract

In this paper, we consider the Byzantine reliable broadcast problem on authenticated and partially connected networks. The state-of-the-art method to solve this problem consists in combining two algorithms from the literature. Handling asynchrony and faulty senders is typically done thanks to Gabriel Bracha's authenticated double-echo broadcast protocol, which assumes an asynchronous fully connected network. Danny Dolev's algorithm can then be used to provide reliable communications between processes in the global fault model, where up to f processes among N can be faulty in a communication network that is at least 2f+1-connected. Following recent works that showed that Dolev's protocol can be made more practical thanks to several optimizations, we show that the state-of-the-art methods to solve our problem can be optimized thanks to layer-specific and cross-layer optimizations. Our simulations with the Omnet++ network simulator show that these optimizations can be efficiently combined to decrease the total amount of information transmitted or the protocol's latency (e.g., respectively, -25% and -50% with a 16B payload, N=31 and f=4) compared to the state-of-the-art combination of Bracha's and Dolev's protocols.