The University of Stuttgart is coordinating a new €6 million research project, QCyber, to develop secure applications for real-world quantum networks. Launched on February 18, 2026, the three-university collaboration will test methods within a fibre-optic network in Stuttgart, connecting up to six nodes over 20 kilometers. QCyber addresses the growing need for multi-user secure communication, moving beyond the limitations of current two-party quantum networks. “Quantum networks studied so far typically connect only two users. But in practice, often multiple parties need to communicate securely at the same time,” says Professor Stefanie Barz of the University of Stuttgart, who leads the project. The initiative, funded by the German Federal Ministry of Research, Technology and Space, aims to bolster technological sovereignty in future IT security, with potential applications ranging from secure finance to verifiable elections.
QCyber Project: Secure Quantum Network Development in Stuttgart
The project’s core innovation lies in addressing a critical gap in current quantum network research. QCyber isn’t solely focused on communication, however; researchers are developing quantum-based methods for applications ranging from secure diplomacy and finance—guaranteeing anonymity—to verifiable “quantum e-voting” systems. Furthermore, the team intends to lay the groundwork for future quantum-based cloud computing through secure computing in networked environments. The network will integrate existing campus fibre infrastructure, supplemented by a test link provided by Nokia, and will be rigorously tested for both functionality and security.
Workshops at ARENA2036 will involve industry representatives to explore deployment scenarios, including secure vehicle communication and protection of smart factory production networks. “With this fundamental yet application-oriented research programme, QCyber aims to make an important contribution to strengthening and securing technological sovereignty in future IT security in Germany and Europe,” Barz asserts.
Multi-User Quantum Applications for Diplomacy & Finance
Beyond the established promise of point-to-point quantum security, researchers are now tackling the complexities of multi-user quantum networks, with implications for sensitive fields like diplomacy and finance. The newly launched QCyber project, coordinated by the University of Stuttgart, directly addresses the limitations of current systems, which “typically connect only two users,” according to Professor Stefanie Barz. This project acknowledges that real-world secure communication frequently demands simultaneous connections between multiple parties. QCyber isn’t solely focused on communication; the team is developing a broad range of applications leveraging this enhanced security.
A key innovation is a secure quantum method for multi-user communication that can also guarantee anonymity—a critical feature for diplomatic channels and financial transactions. Furthermore, the project aims to create systems where information requires collaborative decryption, adding another layer of protection. “Quantum e-voting” is also under development, potentially delivering verifiable and anonymous elections with unprecedented trustworthiness. This real-world testing will assess the viability of the developed hardware and software, alongside its integration with conventional cybersecurity systems.
Quantum networks studied so far typically connect only two users. But in practice, often multiple parties need to communicate securely at the same time.
Real-World Testing on 20km Fibre-Optic Network
Professor Stefanie Barz at the University of Stuttgart is spearheading rigorous real-world testing of quantum communication technologies within a newly established 20km fibre-optic network. This network, integrating existing campus infrastructure and a supplemental link provided by Nokia, connects the Stuttgart campuses of Vaihingen and City Center, forming a crucial testbed for the QCyber joint research project. Researchers are not solely focused on communication; they are developing a diverse range of quantum applications, including secure multi-user communication protocols relevant to sectors like diplomacy and finance.
A key innovation is a method for distributing information requiring collaborative decryption, alongside explorations into “quantum e-voting” for verifiable and anonymous elections. Workshops held at ARENA2036 are actively engaging industry representatives to identify potential deployment scenarios, ranging from secure vehicle communication to safeguarding production networks in smart factories.
