UPM and Q*Bird Launch Spain’s First Multi-Node MDI-QKD Network in Madrid

Why It Matters

The rollout proves that industrial‑scale, trusted‑node‑free quantum encryption can protect critical government infrastructure, bolstering Europe’s digital sovereignty.

Key Takeaways

• First multi-node MDI‑QKD network in Spain
• Connects INTA and Ministry of Interior sites via hub‑spoke
• Uses Q*Bird Falqon® MQX4000 hub, MQS4000 switch
• Operates over 30‑50 km fiber without trusted nodes
• Validates industrial‑grade quantum security for EuroQCI

Pulse Analysis

Quantum key distribution has moved beyond laboratory demos, and MDI‑QKD now offers a pragmatic path to metropolitan security. Unlike conventional QKD, which relies on trusted relays, the measurement‑device‑independent protocol places all detectors in a central node that never accesses the raw keys. This architecture removes a major vulnerability—detector side‑channel attacks—while preserving the unconditional security guarantees promised by quantum physics. For enterprises and governments seeking future‑proof encryption, MDI‑QKD represents a decisive upgrade over classical post‑quantum algorithms.

In Madrid, the collaboration between UPM and Q*Bird leverages the Falqon® series, featuring the MQX4000 hub and MQS4000 optical switch, to interconnect three high‑security sites across 30‑50 km of existing fiber. The hub‑and‑spoke topology creates a fully meshed network without the need for trusted repeaters, enabling seamless key exchange among the Instituto Nacional de Técnica Aeroespacial (INTA) labs and the Ministry of the Interior’s SGSICS office. Early performance data show robust key‑generation rates and loss tolerance comparable to dedicated point‑to‑point links, confirming that the system can operate under real‑world metropolitan conditions.

The Madrid deployment is a cornerstone for the European Quantum Communication Infrastructure (EuroQCI) strategy, demonstrating that scalable, industrial‑grade quantum security is ready for critical national assets. As governments across the continent prioritize digital sovereignty, the successful integration into the Madrid Quantum Communication Infrastructure (MadQCI) signals a market shift toward commercial MDI‑QKD solutions. Vendors can now reference a proven, multi‑node implementation to accelerate rollout in other capitals, while policymakers gain concrete evidence that quantum‑resistant communications can be deployed at scale without compromising operational flexibility.