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The European Quantum Communication Infrastructure Initiative




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Slovenian Quantum Communication Infrastructure Demonstration






      Build architecture and prepare EuroQCI integration

      Improved security

      Industrialization & autonomy

      Deployment & integration

      Measurements and lessons learned

      Train young researchers and engineers

      Grow national expertise



Key Contacts:

      Anton Ramšak Project Coordinator

      Rainer Kaltenbaek – Scientific & Technical Coordinator

      Barbara Dorić – Project Manager




      UL FMF; University of Ljubljana, Faculty of Mathematics and Physics (Anton Ramšak and Rainer Kaltenbaek)



      IJS; Jozef Stefan Institute (Peter Jeglič)

      Beyond Semiconductor (Matjaž Breskvar)

      URSIV; Government Information Security Office (Marjan Kavčič)

      UVTP; Government Office for the Protection of Classified Information (Mojca Mikac)  




The volume of internet traffic increases enormously every year, and with it the number of security breaches and the total number of classified information disclosed. Such developments require increasingly sophisticated protection methods if we are to reduce the risks of potential attacks. Quantum communications is the ultimate physical solution for absolutely secure communications for government, defence, and critical infrastructure. In this scenario, quantum key distribution (QKD) is a protocol that enables unconditionally secure data communications using the laws of quantum physics. In all other (classical) information transmission technologies, it is possible to intercept the transmitted key so that it can be copied without the sender and receiver noticing. In the context of quantum technology, this is not possible, but the implementation itself is technologically extremely demanding, which is also the reason why it is only 100 years after the discovery of the laws of quantum mechanics that their application is slowly gaining acceptance.

The SiQUID (Slovenian Quantum Communication Infrastructure Demonstration) project will establish quantum key distribution links between several state nodes in Slovenia and a test quantum network between research institutions in Ljubljana for advanced quantum communication protocols. We will coordinate our efforts with public and industrial stakeholders and train key personnel, young researchers and engineers in quantum technology. The first test nodes will be establishedbetween research institutions in Ljubljana and will be based on state-of-the-art entanglement distribution protocol. The entangled photons will be generated through a process called spontaneous parametric down conversion. This is a nonlinear optical process taking place in a lithium niobate crystal, integrated in an interferometer. The secret key is generated upon detection. We will choose the detection basis using a high-confidence random number generator. This will form the basis for implementing QKD links between government nodes. To reduce the cost of future QKD networks, SiQUID will investigate the feasibility of cheaper detection node alternatives by balancing cost against the key rates achievable in metropolitan links.

In addition, we will test advanced quantum communication protocols such as
device-independent QKD and remote entanglement to further improve the security of QKD implementations and prepare the ground for a future full-scale quantum communication network. We are in close contact with QCI initiatives in all four neighbouring countries to facilitate harmonisation of national efforts and enable future cross-border interconnections and implementation of the EuroQCI space segment.



Planned QKD network:


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      RIBEZZO, Domenico, PUŠAVEC, Žiga, KALTENBAEK, Rainer, RAMŠAK, Anton, et al. Deploying an inter-European quantum network, Advanced Quantum Technologies  6,  2200061 (2023).