On 17 June, BME hosted the Workshop about Experiences on Building National Quantum Communication Networks, organised within the framework of the QCIHungary project. The event brought together Hungarian consortium partners and international experts to exchange experiences on the development of national quantum communication infrastructures and discuss the latest developments in European collaboration.

The plenary presentations provided an overview of recent progress in the development of national quantum communication networks, ongoing European initiatives, and the technological and cybersecurity challenges associated with deploying quantum communication infrastructures.

Stephan Laschet and Florian Kutschera from the Austrian Institute of Technology (AIT) delivered a presentation title „QCI in Austria: QCI-CAT main outcomes and planned CEF infrastructure. The presentation detailed the outcomes of QCI-CAT, Austria’s national Quantum Communication Infrastructure (QCI) testbed, which concluded in 2026. It highlights the practical implementation of Quantum Key Distribution (QKD) across multiple network topologies, technical performance comparisons of industry hardware, the development of AIT’s Key Management System (KMS) called AURORA, and future scaling plans via Connecting Europe Facility (CEF) projects under the EuroQCI initiative.

Mihai Carabas, the representative from the University POLITEHNICA of Bucharest (UPB) and RoEduNet presented results of the RoNaQCI project. He detailed the large consortium of their NatQCI project, outlined five major goals of their project: Deploy advanced national quantum systems and networks, test, monitor, and integrate quantum systems with existing classical communication infrastructures, develop tailored, advanced use cases benefiting public authorities, governmental entities, academic institutions, and private corporations, create a broad base of trained users via strategic upskilling programs and finally anticipate in wider EU network designs for the arrival of the Quantum Internet. The major achievement of RoNaQCI was to ‭‬1500+ km‭‬‭‬ quantum communication network spanning Romania with a coverage of 36 QKD links connecting 10 universities, 5 research institutes, 5 public bodies, 3 data centers, and a medical clinic and demonstrating the QKD technology.

In his presentation, David Polzoni from the Slovak Academy of Sciences highlighted Slovakia’s SKQCI project, which balances the laboratory prototyping of advanced superconducting single-photon detectors with regional inter-city fiber routing. Ultimately, Slovakia has finalized a robust, fully meshed QKD metropolitan loop in Bratislava connecting vital state institutions under an ETSI-compliant software control plane developed in their NatQCI project.

Mátyás Koniorczyk (Winger FK) from QCIHungary summarized the Hungarian NatQCI project. His presentation introduced the development and architecture of the Hungarian Quantum Key Distribution network under the QCIHungary project. He mentioned, that due to several administrative obstacles QCIHungary project heavily delayed. Finally, QKD hardware from ThinkQuantum is scheduled to arrive starting June 2026, with an operational target for the autumn of 2026 to launch both the national backbone and the Budapest metropolitan network. The national backbone follows a trusted-node chain stretching from Győr through Budapest down to Szeged. Meanwhile, the Budapest metropolitan network connects four key partner sites—Pro-M, Wigner, BME, and ELTE—using a combined spoke-and-chain link topology. Looking ahead, future CEF extensions will expand the network westward from Győr to Rajka to link with Vienna and Bratislava, and eastward from Szeged to Nădlac to connect with Romania. Cultivating vendor interoperability remains a primary focus because the upcoming CEF procurement phases will be open to multi-vendor equipment and alternative Key Management Systems.

The afternoon workshop sessions focused on practical aspects of implementation. The first session addressed opportunities for developing cross-border infrastructure, interoperability between national QCI systems, and issues related to operation, maintenance, and long-term sustainability. The second session examined the architecture of quantum communication networks, authentication and authorisation mechanisms, security frameworks, as well as the challenges of international cooperation and governance.

The workshop highlighted that the development of quantum communication is not only a technological challenge but also requires close international coordination, common standards, and continuous knowledge sharing. Events such as this play a vital role in ensuring that Hungarian developments are closely aligned with the emerging European quantum communication ecosystem and contribute to the establishment of secure and resilient digital communication infrastructures across Europe.