Fully passive entanglement based quantum key distribution scheme

TL;DR

This paper introduces a fully passive entanglement-based quantum key distribution scheme that generates certified random bits from measurement-basis-mismatched photon pairs, eliminating the need for auxiliary random numbers in privacy amplification.

Contribution

It proposes a novel method to extract certified random bits directly from detection events, enhancing the security and practicality of entanglement-based QKD systems.

Findings

Random bits are certified from mismatched measurement events.

The scheme estimates phase error rate for privacy certification.

Extension potential to all practical QKD schemes.

Abstract

In general, generation of entangled photon pairs and also the random choice of measurement basis can be implemented with passive optical devices in entanglement based quantum key distribution (QKD) system. However, auxiliary random numbers are still mandatory for conducting the privacy amplification procedure. In this paper, we propose a fully passive entanglement based QKD scheme in which certified random bits for privacy amplification are extracted from detection events of measurement-basis-mismatched entangled photon pairs. The privacy of these random bits can be certified by estimating the phase error rate in the sifted key. The idea of extracting certified random numbers from measurement-basis-mismatched photons, can be extended to all practical QKD schemes.