Deployment-ready quantum key distribution over a classical network infrastructure in Padua

M. Avesani¹, G. Foletto¹, M. Padovan¹, L. Calderaro¹, C. Agnesi¹, E. Bazzani¹, F. Berra¹, T. Bertapelle¹, F. Picciariello¹, F. B.L. Santagiustina¹, D. Scalcon¹, A. Scriminich¹, A. Stanco¹, F. Vedovato¹, G. Vallone¹, and P. Villoresi¹
J. Light. Technol. 40 (6), 1658 – 1663 (2022)
DOI:10.1109/JLT.2021.3130447

¹Department of Information Engineering, University of Padova, via Gradenigo 6/B, 35131 Padova, Italy

Current technological progress is driving Quantum Key Distribution towards a commercial and world widescale expansion. Its capability to deliver unconditionally secure communication will be a fundamental feature in the next generations of telecommunication networks. Nevertheless, demonstrations of QKD implementation in a real operating scenario and their coexistence with the classical telecom infrastructure are of fundamental importance for reliable exploitation. Here we present a Quantum Key Distribution application implemented overa classical fiber-based infrastructure. By exploiting just a single fiber cable for both the quantum and the classical channel and by using a simplified receiver scheme with just one single-photon detector, we demonstrate the feasibility of low-cost and ready-to-use Quantum Key Distribution systems compatible with standard classical infrastructure.