W-state Analyzer and Multi-party Measurement-device-independent Quantum Key Distribution

TL;DR

This paper introduces a novel multi-party measurement-device-independent quantum key distribution protocol based on W-states, including a W-state analyzer, security proof, and performance simulation, advancing multi-party quantum communication.

Contribution

It presents the first multi-party MDI-QKD protocol using W-states, with a designed linear optics W-state analyzer and comprehensive security analysis.

Findings

Feasible over 150 km telecom fiber with standard detectors

Complete security proof established for the protocol

Numerical simulations demonstrate practical performance

Abstract

W-state is an important resource for many quantum information processing tasks. In this paper, we for the first time propose a multi-party measurement-device-independent quantum key distribution (MDI-QKD) protocol based on W-state. With linear optics, we design a W-state analyzer in order to distinguish the four-qubit W-state. This analyzer constructs the measurement device for four-party MDI-QKD. Moreover, we derived a complete security proof of the four-party MDI-QKD, and performed a numerical simulation to study its performance. The results show that four-party MDI-QKD is feasible over 150 km standard telecom fiber with off-the-shelf single photon detectors. This work takes an important step towards multi-party quantum communication and a quantum network.