An efficient validated asynchronous byzantine agreement protocol using committee

TL;DR

This paper introduces a validated asynchronous Byzantine agreement protocol that improves efficiency by stochastic subset selection for broadcasting requests, reducing message and computation overhead despite increased time complexity.

Contribution

It proposes a novel approach allowing only a subset of parties to broadcast requests, enhancing efficiency over traditional multi-valued Byzantine agreement protocols.

Findings

Reduces message complexity compared to traditional protocols

Achieves lower computational overhead

Maintains correctness and validation properties

Abstract

We present a Byzantine agreement protocol to address the inefficiencies inherent in multi-valued Byzantine agreement protocols, i.e., a version of the Byzantine agreement protocol where every party broadcasts its request, and at the end of the protocol, every party agrees on one of the party's requests. The protocol we present is a validated asynchronous Byzantine agreement protocol, i.e., a party's request must be validated by some external validity property before it is proposed for agreement. Differently from most of the MVBA protocols, we allow only a subset of total parties to broadcast their requests instead of all, and we make the subset selection stochastic each time the parties choose to broadcast a new set of requests. Then, at the time of the agreement, we choose a party from the selected subset, and the parties reach an agreement on the selected party's broadcast. Extensive theoretical analysis shows that this approach can produce efficient output regarding messages and computation overhead, but the protocol is time-consuming.