Locked Shields is the world’s largest and most complex international live-fire cyber defence exercise, hosted annually by the NATO Cooperative Cyber Defence Centre of Excellence (CCDCOE) since 2010.
The exercise aims to strengthen and enhance the cyber defence capabilities of participating nations, promote public, private, and multinational cooperation, and accelerate innovation across the cyber domain.
It simulates a realistic, large-scale live-fire cyber conflict, testing participants’ technical, operational, and strategic capabilities alongside decision-making under pressure. It also incorporates legal and communication considerations, fostering a wartime mentality that compels teams to think quickly, adapt to unexpected threats, and collaborate effectively.
The exercise addresses the protection of vital services and critical infrastructure that are fundamental for modern societies to operate as well as keeping up and running the military infrastructure. All the systems involved in use reflect authentic risks and real-life scenarios.
The 2026 iteration is expected to bring together approximately 4,000 participants from 40 nations.