Multipartite Continuous Variable Solution for the Byzantine Agreement Problem

TL;DR

This paper presents a continuous-variable quantum protocol using multipartite Gaussian states to solve the Byzantine Agreement problem, demonstrating robustness under realistic noise and detector inefficiencies.

Contribution

It introduces a novel continuous-variable approach to Byzantine Agreement using Gaussian states, highlighting entanglement thresholds and practical implementation considerations.

Findings

Protocol is robust against noise and detector inefficiencies

Minimum entanglement required for solution identified

Feasible with current Gaussian state technology

Abstract

We demonstrate that the Byzantine Agreement (detectable broadcast) is also solvable in the continuous-variable scenario with multipartite entangled Gaussian states and Gaussian operations (homodyne detection). Within this scheme we find that Byzantine Agreement requires a minimum amount of entanglement in the multipartite states used in order to achieve a solution. We discuss realistic implementations of the protocol, which consider the possibility of having inefficient homodyne detectors, not perfectly correlated outcomes, and noise in the preparation of the resource states. The proposed protocol is proven to be robust and efficiently applicable under such non-ideal conditions.