Fully passive Measurement Device Independent Quantum Key Distribution

TL;DR

This paper introduces a fully passive measurement-device-independent quantum key distribution scheme that enhances security by eliminating side channels from source modulators and measurement attacks, supported by a specific encoding strategy and simulation results.

Contribution

It proposes a novel fully passive MDI-QKD protocol that improves security against source and measurement attacks using passive encoding and decoy-state analysis.

Findings

Secure key rate demonstrated through simulation

Protection against source side channels and measurement attacks

Feasible implementation with realistic devices

Abstract

Measurement-device-independent quantum key distribution (MDI-QKD) can resist all attacks on the detection devices, but there are still some security issues related to the source side. One possible solution is to use the passive protocol to eliminate the side channels introduced by active modulators at the source. Recently, a fully passive QKD protocol has been proposed that can simultaneously achieve passive encoding and passive decoy-state modulation using linear optics. In this work, we propose a fully passive MDI-QKD scheme that can protect the system from both side channels of source modulators and attacks on the measurement devices, which can significantly improve the implementation security of the QKD systems. We provide a specific passive encoding strategy and a method for decoy-state analysis, followed by simulation results for the secure key rate in the asymptotic scenario. Our work offers a feasible way to improve the implementation security of QKD systems, and serves as a reference for achieving passive QKD schemes using realistic devices.