Experimental demonstration of a quantum protocol for Byzantine agreement and liar detection

TL;DR

This paper presents a new quantum protocol for Byzantine agreement and liar detection, based on four-qubit entanglement, with a simplified classical part and an experimental demonstration using four-photon entanglement.

Contribution

It introduces a novel quantum protocol for Byzantine agreement and liar detection, leveraging four-qubit entanglement, with an experimentally implemented proof-of-concept.

Findings

Successful experimental implementation with four-photon entanglement

Simpler classical protocol compared to previous methods

Effective quantum solution for Byzantine agreement and liar detection

Abstract

We introduce a new quantum protocol for solving detectable Byzantine agreement (also called detectable broadcast) between three parties, and also for solving the detectable liar detection problem. The protocol is suggested by the properties of a four-qubit entangled state, and the classical part of the protocol is simpler than that of previous proposals. In addition, we present an experimental implementation of the protocol using four-photon entanglement.