Key rate enhancement using qutrit states for uncharacterized quantum key distribution

TL;DR

This paper introduces a 3-dimensional quantum state protocol for measurement-device-independent quantum key distribution, enhancing key rates especially with uncharacterized sources, by leveraging mismatched-basis statistics analysis.

Contribution

It proposes a novel 3d-MDI-QKD protocol that improves key rates and security analysis for uncharacterized sources, extending the capabilities of existing qubit-based methods.

Findings

The 3d-MDI-QKD protocol achieves higher secret key rates than qubit-based protocols in certain regimes.

Security is analyzed considering uncharacterized sources with unwanted states.

Simulation results demonstrate the protocol's advantage over traditional qubit MDI-QKD.

Abstract

It is known that measurement-device-independent quantum key distribution (MDI-QKD) provides ultimate security from all types of side-channel attack against detectors at the expense of low key generation rate. Here, we propose MDI-QKD using 3-dimensional quantum states and show that the protocol improves the secret key rate under the analysis of mismatched-basis statistics. Specifically, we analyze security of the 3d-MDI-QKD protocol with uncharacterized sources, meaning that the original sources contain unwanted states instead of expected one. We simulate secret key rate of the protocol and identify the regime where the key rate is higher than the protocol with the qubit MDI-QKD.