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

Sascha Gaertner, Mohamed Bourennane, Christian Kurtsiefer, Adan Cabello, Harald Weinfurter

Published 2007-10-01, updated 2008-02-23Version 2

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.