Consortium demonstrates Quantum Key Distribution for critical Infrastructures across 680 Kilometers:
The project “Integration von QKD in IKT-Netze (Q‑net‑Q),” funded by the Bundesministerium für Forschung, Technologie und Raumfahrt (BMFTR) and co-funded by the European Union under the EFRE programme, aimed to integrate Quantum Key Distribution (QKD) into existing information and communication technology (ICT) systems. Based on a comprehensive scientific analysis, a systematic transfer of expertise and technology between the QKD and ICT domains was developed. After more than three years, the consortium led by Hochschule Nordhausen successfully completed the project. In addition to the Technical Universities of Berlin and Munich, the Friedrich-Alexander-Universität Erlangen-Nürnberg and DE-CIX Management GmbH, the SQuaD partners Fraunhofer-Institut für Nachrichtentechnik, Heinrich-Hertz-Institut (HHI) and Fraunhofer-Institut für Angewandte Optik und Feinmechanik (IOF) were involved. The project resulted in the successful implementation of Quantum Communication beyond controlled laboratory environments. At a final presentation held in late February 2026, the consortium demonstrated key components and application scenarios of a QKD-secured network.
At the Gesundheitspark Sundhausen, the consortium demonstrated the functionality of a 150-kilometer regional testbed. This was connected via a long-distance link spanning a total of 680 kilometers from Fraunhofer HHI in Berlin via Erfurt to Frankfurt am Main. The practical application was illustrated through a realistic teleconsultation between Sundhausen and Jena. At the local health kiosk, an eHealth system was used to collect vital parameters such as pulse rate and oxygen saturation. These sensitive data were encrypted via a Quantum Access Point and transmitted in real time. With this successful demonstration, the consortium validated the integration of QKD into existing ICT networks for securing highly sensitive data. The results underline the operational readiness of QKD systems under real-world conditions.
For the research activities, the partners had access to four testbeds. In addition to the regional connection in Sundhausen, the consortium investigated the performance of key generation over a large-scale long-distance link. This link extended from the internet exchange DE-CIX in Frankfurt via Erfurt to Fraunhofer HHI in Berlin, covering more than 680 kilometers of quantum-secured optical fiber infrastructure. The central node of this infrastructure was the Fraunhofer Center in Erfurt, led by Fraunhofer IOF. The successful demonstration shows that interoperable Quantum Communication over long distances can already be integrated into existing regional infrastructure systems today – providing a realistic perspective for the protection of critical infrastructures. Click here for more information about Q‑net‑Q.
Source references: https://www.hhi.fraunhofer.de/en/press/news/quantum-communication-in-real-world-applications-research-consortium-validates-hybrid-network-architectures-over-680-kilometers.html; https://www.forschung-it-sicherheit-kommunikationssysteme.de/projekte/q‑net‑q