A cyberattack occurs every 39 seconds. This alarming statistic(*) highlights the constant threat to today’s security systems. But an even bigger challenge lies ahead with the onset of quantum computers. Current encryption techniques are safe for now. But, ongoing tech advances will soon make them a risk.
To address this shift, the SnT has been driving research in Quantum Key Distribution (QKD). This secure method uses quantum mechanics to generate unbreakable encryption keys that are theoretically unbreakable. A few weeks ago, researchers reached a milestone: they established a QKD connection between Luxembourg and Belgium.
The ultimate goal? An interconnected European network that is resilient to quantum threats.
The LUQCIA initiative: advancing QKD research
In 2022, SnT launched LUQCIA (LUxembourg Quantum Communication Infrastructure lAb). It will build a national testbed for quantum communication and advance research in this field. This five-year project is funded by the European Union – Next Generation EU. It is a collaboration with the Luxembourgish Government’s Department of Media, Connectivity and Digital Policy, under the RRF program.
Since the project’s launch, the SnT research team has made great strides. First, they set up their Quantum Key Lab to host collaborative research. Then, they conducted a year-long QKD demonstration between the University of Luxembourg’s Kirchberg and Belval campuses.
While testing this national connection, the team prepared for their next objective: to move beyond national borders.
Demonstrating quantum-safe communication across borders
The project faced many challenges. First, SnT needed to find the right partner across the border, not too far from the University. Indeed, distance matters when it comes to QKD. Every kilometre of fibre optic cable raises the risk of losing quantum particles (known as photons) that carry the encryption information.
SnT teamed up with BeQCI, a Belgian consortium in the European EuroQCI initiative. The Belgian node for the QKD connection was set up in a data centre located in Arlon, about 40 km from the University. The data centre is managed by Belnet, a key partner within BeQCI as the National Research & Education Network. They provide technical support and access to infrastructure.
Setting up in Arlon is not only convenient, it’s also a strategic move. Located near the European Space Agency (ESA) Redu centre, the site is ideal for future experiments involving satellite integration. These are key to extending QKD over long distances.
Next, the project required finding suitable QKD devices. It also needed coordinating efforts between different service providers for the dark fibre installation. SnT worked with LuxConnect for the Luxembourgish segment and Sofico for the Belgian side to connect the fibre link.
After some technical setbacks, the QKD connection was established on 17 October 2024. Since then, SnT and Belnet have been successfully exchanging encryption keys. This is a major achievement as QKD is a very sensitive communication method.
Ongoing testing and next steps
Now that the link is up and running, SnT is monitoring its reliability and performance. The goal is to gather data on key exchange rates. Researchers will observe how various factors, like time of day and temperature, impact communication.
The connection is set to run until the end of 2024, but the SnT team wants to extend it to collect more insights. They could go beyond proving technical feasibility, and instead work on promising applications. For example they could securely exchange sensitive data between high-performance computing centres.
Paving the way for pan-European quantum communication
As nations are preparing to protect their data and critical infrastructure, their goal is clear: to build a European quantum-secure network. This cross-border demonstration is an important step toward that goal. It also gives a significant boost to Luxembourg’s expertise in QKD communication and cybersecurity.
“This milestone particularly noteworthy. SnT deployed its own QKD network, including a cross-border link, within a short time,” concludes Jorge Luis Gonzalez Rios, SnT’s QCI Lab tech coordinator. “The team built their expertise virtually from scratch, proving that smaller countries can be significant players in quantum communication infrastructure.”
Next on the horizon? Connecting the QKD network with space. Fibre networks and satellite links should boost Europe’s communications.
(*) University of Maryland’s A. James Clark School of Engineering