The Croatian Quantum Communication Infrastructure (CroQCI) project presentation took place on May 7, 2024, in the National and University Library hall. As the leader of the fourth Work Package of the CroQCI project, FER is responsible for the space segment of quantum communications.

The project involves a team of scientists from the Department of Communication and Space Technologies (ZKIST): Prof. Dr. Dubravko Babić as the project leader, Assist. Prof. Dr. Josip Vuković as a team member, and Assist. Prof. Dr. Josip Lončar, Bruno Skendrović, Jasna Janković, and Mate Jagnjić as technical leaders, along with Assist. Prof. Dr. Marko Horvat from the Department of Applied Computing. For the educational package within the sixth Work Package of the CroQCI project, Assoc. Prof. Dr. Saša Ilijić from the Department of Applied Physics is responsible on behalf of FER.

CroQCI represents a system that uses the principles of quantum mechanics for data transmission. Popularly called the "quantum internet," it offers greater security and higher data transmission capacities compared to cryptographic communication systems and will be part of the broader European infrastructure. This advanced form of communication has potential applications in areas such as communication security, computing, and network technologies, preventing unauthorized intrusions into internet channels, eavesdropping, and theft of sensitive data.

The presentation of the CroQCI project was attended by the Dean of FER, Prof. Dr. Vedran Bilas, and representatives from ZKIST, Prof. Dr. Sonja Grgić, and the head of the department, Prof. Dr. Gordan Šišul. In the introductory presentation, Prof. Dr. Dubravko Babić participated as a panelist, while Assoc. Prof. Dr. Saša Ilijić participated in the closing panel.

The goal of the Work Package our FER team is responsible for is the construction of Croatia's first optical ground station for quantum communications, which will receive single-photon states from the European low-orbit satellite Eagle-1, implementing the decoy-based BB84 protocol. The station will thus serve as a mediator for quantum key distribution between locations within the European Union.

The optical ground station for quantum communications is the first of its kind in Croatia and one of seven planned in the European Union within the EuroQCI project. The design and implementation of such a station result from the transfer of technology and knowledge at the highest levels, including the German Aerospace Center (DLR), which was visited by a special delegation from FER and IRB, establishing a strategic collaboration. FER will also be a quantum node in the terrestrial quantum communication infrastructure, which will connect consortium members within an ultra-secure network protected by the principles of quantum mechanics using optical fibers.

The optical ground station will be a quantum gateway for Croatia, connecting locations that currently cannot be efficiently connected via terrestrial quantum communications.