Modular quantum key distribution setup for research and development applications

TL;DR

This paper presents a flexible, modular quantum key distribution setup with open source software, enabling research, education, and rapid prototyping of QKD protocols, including decoy-state BB84 for secure long-distance communication.

Contribution

The authors introduce a versatile, open source modular QKD platform that supports protocol modification and real-world testing, advancing research and development in quantum communication.

Findings

Successful implementation of decoy-state protocol for secure long-distance QKD.

Robustness demonstrated in urban QKD experiments beyond laboratory conditions.

Open source tools facilitate protocol testing and system customization.

Abstract

Quantum key distribution (QKD), ensuring the unconditional security of information, attracts a significant deal of interest. An important task is to design QKD systems as a platform for education as well as for research and development applications and fast prototyping new QKD protocols. Here we present a modular QKD setup driven by National Instruments (NI) cards with open source LabView code, open source Python code for post-processing procedures, and open source protocol for external applications. An important feature of the developed apparatus is its flexibility offering possibilities to modify optical schemes and verify novel QKD protocols. Another distinctive feature of the developed setup is the implementation of the decoy-state protocol, which is a standard tool for secure long-distance quantum communications. By testing the plug-and-play scheme realizing BB84 and decoy-state BB84 QKD protocols, we demonstrate that developed QKD setup shows a high degree of robustness beyond laboratory conditions. We demonstrate the results of the use of the developed modular setup for urban QKD experiments.