Detector-Device-Independent Quantum Key Distribution

TL;DR

This paper introduces a simplified quantum key distribution scheme that uses a two-qubit single-photon approach, enhancing practicality and efficiency over traditional measurement-device-independent QKD methods.

Contribution

It presents an experimental demonstration of a TQSP-based QKD scheme that removes the need for two-photon interference, simplifying implementation and improving efficiency.

Findings

Eliminates the need for interference between independent photons.

Reduces experimental complexity of mdiQKD.

Improves key generation rate and practicality.

Abstract

Recently, a quantum key distribution (QKD) scheme based on entanglement swapping, called measurement-device-independent QKD (mdiQKD), was proposed to bypass all detector side-channel attacks. While mdiQKD is conceptually elegant and offers a supreme level of security, the experimental complexity is challenging for practical systems. For instance, it requires interference between two widely separated independent single-photon sources, and the rates are dependent on detecting two photons - one from each source. Here we experimentally demonstrate a QKD scheme that removes the need for a two-photon system and instead uses the idea of a two-qubit single-photon (TQSP) to significantly simplify the implementation and improve the efficiency of mdiQKD in several aspects.