Iterative Approximate Byzantine Consensus under a Generalized Fault Model

TL;DR

This paper introduces a generalized fault model for iterative approximate Byzantine consensus in directed networks, encompassing various failure scenarios, and establishes a necessary and sufficient condition for the existence of such algorithms.

Contribution

It proposes a broad fault model that unifies previous models and provides a fundamental condition for the feasibility of IABC algorithms under this model.

Findings

Unified fault model encompassing prior models

Necessary and sufficient condition for IABC existence

Enhanced understanding of fault tolerance in networks

Abstract

In this work, we consider a generalized fault model that can be used to represent a wide range of failure scenarios, including correlated failures and non-uniform node reliabilities. This fault model is general in the sense that fault models studied in prior related work, such as f -total and f -local models, are special cases of the generalized fault model. Under the generalized fault model, we explore iterative approximate Byzantine consensus (IABC) algorithms in arbitrary directed networks. We prove a necessary and sufficient condition for the existence of IABC algorithms. The use of the generalized fault model helps to gain a better understanding of IABC algorithms.