A Reconfigurable Multilayer Quantum Key Distribution Network over Existing Metropolitan Fibre
Abstract
Scaling quantum networks requires architectures extending end-to-end service reachability despite constrained fibre and equipment. Critically, in brownfield deployments, the quantum network must be engineered around classical telecommunications infrastructure and the operating capabilities of quantum key distribution (QKD) technology. To address this, we demonstrate a seven-node, multilayer QKD network deployed over existing metropolitan fibre. The implementation compares spectral management techniques to accommodate inherited constraints across its layers. It combines a trusted-node ring with a three-node subnetwork interconnected through reconfigurable optical switching, extending physical connectivity and service reachability without an additional transmitter. A meshed key management layer maps endpoint requests onto trusted-relay paths and supplies Layer 1, Layer 3, and one-time-pad applications. Over 73 days, eight link configurations generated 119.4 Gbit of secret key material with 99.1% link availability. Randomised end-to-end requests revealed indirect cross-layer coupling between key consumption, stored-key state and quantum-layer reconfiguration, demonstrating resource sharing through reconfigurability, spectral multiplexing and logical key-management abstraction.
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BibTeX
@misc{minder2026reconfigurable,
title = {{A Reconfigurable Multilayer Quantum Key Distribution Network over Existing Metropolitan Fibre}},
author = {Mariella Minder and Andreas Siakolas and Elizabeth Pasatembou and Stylianos Mavrikos and Stephanos Yerolatsitis and Konstantinos Katzis and Kyriacos Kalli},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.24561},
eprint = {2609.24561},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.24561},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - A Reconfigurable Multilayer Quantum Key Distribution Network over Existing Metropolitan Fibre
AU - Mariella Minder
AU - Andreas Siakolas
AU - Elizabeth Pasatembou
AU - Stylianos Mavrikos
AU - Stephanos Yerolatsitis
AU - Konstantinos Katzis
AU - Kyriacos Kalli
PY - 2026
DA - 2026/09/21
PB - arXiv
DO - 10.48550/arxiv.2609.24561
UR - https://arxiv.org/abs/2609.24561
AB - Scaling quantum networks requires architectures extending end-to-end service reachability despite constrained fibre and equipment. Critically, in brownfield deployments, the quantum network must be engineered around classical telecommunications infrastructure and the operating capabilities of quantum key distribution (QKD) technology. To address this, we demonstrate a seven-node, multilayer QKD network deployed over existing metropolitan fibre. The implementation compares spectral management techniques to accommodate inherited constraints across its layers. It combines a trusted-node ring with a three-node subnetwork interconnected through reconfigurable optical switching, extending physical connectivity and service reachability without an additional transmitter. A meshed key management layer maps endpoint requests onto trusted-relay paths and supplies Layer 1, Layer 3, and one-time-pad applications. Over 73 days, eight link configurations generated 119.4 Gbit of secret key material with 99.1% link availability. Randomised end-to-end requests revealed indirect cross-layer coupling between key consumption, stored-key state and quantum-layer reconfiguration, demonstrating resource sharing through reconfigurability, spectral multiplexing and logical key-management abstraction.
ER -