Broadcast Using Certified Propagation Algorithm in Presence of Byzantine Faults

TL;DR

This paper establishes a precise condition on network topology ensuring the correctness of the Certified Propagation Algorithm for broadcast in networks with Byzantine faults, addressing an open problem in the field.

Contribution

It provides the first tight necessary and sufficient condition for CPA correctness in Byzantine fault scenarios, advancing understanding of fault-tolerant broadcast.

Findings

Tight necessary and sufficient condition for CPA correctness

First solution to the open problem in prior work

Extensions of the main result for broader applicability

Abstract

We explore the correctness of the Certified Propagation Algorithm (CPA) [6, 1, 8, 5] in solving broadcast with locally bounded Byzantine faults. CPA allows the nodes to use only local information regarding the network topology. We provide a tight necessary and sufficient condition on the network topology for the correctness of CPA. To the best of our knowledge, this work is the first to solve the open problem in [8]. We also present some simple extensions of this result