An Approach to Optimizing the VABA Protocol Using $\kappa$-size Committee

TL;DR

The paper introduces eVABA, an optimized asynchronous Byzantine agreement protocol that reduces communication costs by limiting broadcasts to a subset of parties, improving efficiency in multi-valued agreement scenarios.

Contribution

It presents a novel approach to reduce message complexity in ABA protocols by utilizing a $3$-size committee, enhancing scalability and efficiency.

Findings

Reduces communication overhead in ABA protocols.

Maintains correctness and termination guarantees.

Improves scalability in multi-valued Byzantine agreement.

Abstract

Byzantine agreement protocols in asynchronous networks have gained renewed attention due to their independence from network timing assumptions to ensure termination. Traditional asynchronous Byzantine agreement protocols require every party to broadcast its requests (e.g., transactions), leading to high communication costs as parties ultimately agree on one party's request. This inefficiency is particularly significant in multi-valued Byzantine agreement protocols, where parties aim to agree on one party's requests under the assumption $n=3f+1$, where $n$ is the total number of parties, and $f$ is the number of Byzantine parties. To address these inefficiencies, we propose Efficient-VABA (eVABA), an optimized protocol for the asynchronous Byzantine agreement (ABA) problem. By limiting broadcasts to a selected subset of parties, the protocol reduces the number of messages and computation overhead.