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.
@article{arxiv.0710.0290,
title = {Experimental demonstration of a quantum protocol for Byzantine agreement and liar detection},
author = {Sascha Gaertner and Mohamed Bourennane and Christian Kurtsiefer and Adan Cabello and Harald Weinfurter},
journal= {arXiv preprint arXiv:0710.0290},
year = {2009}
}