Credit: ADIV-SGRS
On Friday 16 May 2025, the Luxembourg Army reported that the Grand Duchy had recently taken part in the Locked Shields 2025 cyber defence exercise, joining forces with Belgium and Latvia for the large-scale event organised by the NATO Cooperative Cyber Defence Centre of Excellence (CCDCOE) in Tallinn, Estonia.
The Luxembourg Army reported that this is the world’s largest international live-fire cyber defence exercise, involving more than 4,000 experts from 41 countries this year.
Over the course of four days, participating teams were tasked with responding to a series of complex, realistic cyberattacks targeting a fictional country named “Berylia”. The exercise tested teams' ability to react and coordinate in response to threats against critical systems such as energy supply infrastructure, communication networks and satellite systems.
According to the Luxembourg Army, the joint Belgium–Latvia–Luxembourg "blue team", made up of 260 experts, successfully defended Berylia’s digital infrastructure, achieving an impressive 4th place out of seventeen competing teams.
The Luxembourg Army also noted the strong performance of the legal subcomponent led by its own representatives, which earned 1st place among all legal teams participating in the exercise. This recognition highlights what it described as the “expertise and professionalism” of Luxembourg’s legal specialists in the field of cyber defence.
In its assessment, the Luxembourg Army described Locked Shields as a “demanding exercise” simulating a large-scale cyber crisis. It emphasised the importance of coordination between technical, legal, communications, and strategic analysis teams. The 2025 edition reportedly further “strengthened participants’ decision-making skills, cyber incident management capabilities, and multinational cooperation.”
The Luxembourg Defence Directorate emphasised that the exercise aligns with its cyber defence strategy, focused on cyber resilience, the development of cyber expertise and international cooperation. Luxembourg’s Defence expressed its appreciation to all participating Luxembourg personnel for their exemplary commitment and welcomed the excellent cooperation with its Belgian and Latvian partners.
