Parameterizable Byzantine Broadcast in Loosely Connected Networks

TL;DR

This paper introduces a parameterizable, non-cryptographic broadcast protocol for loosely connected networks that guarantees reliable information delivery without requiring nodes to know their network positions, outperforming previous solutions.

Contribution

It presents a novel deterministic technique for selecting nodes that always deliver authentic information, applicable without prior network knowledge, improving Byzantine fault tolerance in dynamic networks.

Findings

Protocol significantly outperforms previous solutions under similar assumptions.

The technique reliably identifies nodes that deliver authentic information.

Experimental evaluation demonstrates the protocol's effectiveness.

Abstract

We consider the problem of reliably broadcasting information in a multihop asynchronous network, despite the presence of Byzantine failures: some nodes are malicious and behave arbitrarly. We focus on non-cryptographic solutions. Most existing approaches give conditions for perfect reliable broadcast (all correct nodes deliver the good information), but require a highly connected network. A probabilistic approach was recently proposed for loosely connected networks: the Byzantine failures are randomly distributed, and the correct nodes deliver the good information with high probability. A first solution require the nodes to initially know their position on the network, which may be difficult or impossible in self-organizing or dynamic networks. A second solution relaxed this hypothesis but has much weaker Byzantine tolerance guarantees. In this paper, we propose a parameterizable broadcast protocol that does not require nodes to have any knowledge about the network. We give a deterministic technique to compute a set of nodes that always deliver authentic information, for a given set of Byzantine failures. Then, we use this technique to experimentally evaluate our protocol, and show that it significantely outperforms previous solutions with the same hypotheses. Important disclaimer: these results have NOT yet been published in an international conference or journal. This is just a technical report presenting intermediary and incomplete results. A generalized version of these results may be under submission.