Fully Passive Measurement-Device-Independent Quantum Key Distribution

TL;DR

This paper demonstrates that combining fully passive sources with measurement-device-independent quantum key distribution enhances security and practicality, reducing side channels and maintaining acceptable key rates.

Contribution

It proves the compatibility of fully passive protocols with MDI-QKD and introduces a novel idea to improve sifting efficiency.

Findings

Acceptable key rates achieved with passive MDI-QKD

Enhanced security by removing source and detector side channels

Simplified implementation compared to fully passive TF-QKD

Abstract

A recently proposed fully passive QKD removes all source modulator side channels. In this work, we combine the fully passive sources with MDI-QKD to remove simultaneously side channels from source modulators and detectors. We show a numerical simulation of the passive MDI-QKD, and we obtain an acceptable key rate while getting much better implementation security, as well as ease of implementation, compared with a recently proposed fully passive TF-QKD, paving the way towards more secure and practical QKD systems. We have proved that a fully passive protocol is compatible with MDI-QKD and we also proposed a novel idea that could potentially improve the sifting efficiency.