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arXiv · 2604.05599

PQC-Enhanced QKD Networks: A Layered Approach

Paul Spooren·Andreas Neuhold·Sebastian Ramacher·Thomas Hühn
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Abstract

We present a layered and modular network architecture that combines Quantum Key Distribution (QKD) and Post-Quantum Cryptography (PQC) to provide scalable end-to-end security across long distance multi-hop, trusted-node quantum networks. To ensure interoperability and efficient practical deployment, hop-wise tunnels between physically secured nodes are protected by WireGuard with periodically rotated pre-shared keys sourced via the ETSI GS QKD 014 interface. On top, Rosenpass performs a PQC key exchange to establish an end-to-end data channel without modifying deployed QKD devices or network protocols. This dual-layer composition yields post-quantum forward secrecy and authenticity under practical assumptions. We implement the design using open-source components and validate and evaluate it in simulated and lab test-beds. Experiments show uninterrupted operation over multi-hop paths, low resource footprint and fail-safe mechanisms. We further discuss the design's compositional security, wherein the security of each individual component is preserved under their combination and outline migration paths for operators integrating QKD-aware overlays in existing infrastructures.

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Paul Spooren, Andreas Neuhold, Sebastian Ramacher, Thomas Hühn. 2026-04-07. PQC-Enhanced QKD Networks: A Layered Approach. https://doi.org/10.1109/qcnc69040.2026.00060

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