Universidad Politécnica de Madrid (UPM) and quantum firm Q*Bird have brought an operational MDI-QKD network online in Madrid, the first of its kind in Spain. The deployment uses Q*Bird’s Falqon Series hardware to demonstrate real-world quantum-secure key distribution and support research into performance and interoperability.
MDI-QKD: Unrivaled Security Against Quantum Threats
Measurement-Device-Independent Quantum Key Distribution separates the most vulnerable components of a QKD system by placing detectors at an untrusted central node. That design removes measurement-stage vulnerabilities that adversaries often exploit, because secret keys are never reconstructed at the detector site. Compared with traditional QKD, MDI-QKD offers a higher assurance that even flawed or tampered detectors will not leak key material, making it a strong foundation for future quantum-resilient networks.
UPM and Q*Bird’s Pioneering Collaboration
The Madrid network pairs UPM’s academic testbed capabilities with Q*Bird’s Falqon Series: the MQX4000 hub, MQS4000 switch, and MQT4000 user nodes. These components enable centralised measurement with distributed user nodes, supporting experiments on key generation rates, latency, and multi-node interoperability under deployed fiber conditions. The collaboration focuses on measurable metrics that matter to operators and researchers, validating both performance and practical deployment workflows ahead of broader rollouts.
A Cornerstone for Europe’s Quantum Future
Spain’s operational MDI-QKD link strengthens Southern Europe’s quantum footprint and feeds into regional efforts such as MadQCI and the wider EuroQCI initiative. By proving an interoperable, scalable architecture in a metropolitan environment, the project contributes to building continental quantum communications that support digital sovereignty and sensitive public and private-sector services. The emphasis on standards-ready hardware and measurable field results makes this deployment a replicable model across Europe.
Conclusion
The UPM and Q*Bird network turns an advanced QKD variant from theory into practice. As researchers measure real-world performance and operators test integration scenarios, Spain’s MDI-QKD deployment stands as a concrete step toward operational, quantum-secure infrastructure across Europe.
