Key Takeaways
- Locked Shields 2026, the world’s largest live‑fire cyber defence exercise, gathered over 4,000 participants from 41 nations, matching the 2025 turnout.
- Organized by the NATO Cooperative Cyber Defence Centre of Excellence (CCDCOE) in Tallinn, Estonia, the drill simulated real‑time attacks on critical infrastructure such as air defence systems and e‑voting platforms, while also testing responses to disinformation and political pressure.
- Sixteen multinational teams competed; the top‑scoring joint teams were France & Sweden, Latvia & Singapore, and a quartet of Germany, Austria, Luxembourg, and Switzerland.
- Exercise officials highlighted strong detection and response capabilities, stressed the importance of translating lessons into operational readiness, and underscored the growing role of artificial intelligence in both defending and attacking cyber assets.
- Locked Shields has grown dramatically since its inception in 2010, expanding from four nations and 60 participants to a truly global, multilateral effort that builds trust, shared understanding, and resilience across allied cyber forces.
Overview of Locked Shields 2026
Locked Shields 2026 concluded on Friday after a week‑long, high‑intensity cyber defence exercise that brought together more than 4,000 participants from 41 nations. Hosted by the NATO Cooperative Cyber Defence Centre of Excellence (CCDCOE) in Tallinn, Estonia, the event is recognized as the world’s largest live‑fire cyber defence drill. Its primary purpose is to stress‑test the ability of national and multinational teams to defend critical infrastructure and military networks against sophisticated, real‑time cyber threats while maintaining essential services under pressure.
Participation Scale and Consistency
The exercise attracted the same number of participants as its 2025 predecessor—over 4,000 individuals representing a diverse array of government, military, academic, and private‑sector entities. This steadfast turnout underscores the enduring commitment of NATO allies and partner nations to invest in collective cyber readiness. The geographic spread, ranging from North America and Europe to Asia‑Pacific, reflects the increasingly global nature of cyber threats and the necessity for a coordinated, multinational response.
Simulation Objectives and Tasked Challenges
During Locked Shields 2026, teams were tasked with protecting a range of vital systems, including air defence architectures, electronic voting platforms, power grid components, and telecommunications networks. Beyond pure technical defence, the exercise deliberately incorporated elements of information warfare: participants had to contend with coordinated disinformation campaigns, fake news injections, and political pressure designed to sow confusion and erode decision‑making confidence. By blending kinetic‑style cyber attacks with influence operations, the drill mirrored the hybrid threat landscape that modern states confront daily.
Performance Results and Leading Teams
Sixteen multinational teams competed for the highest scores, which were awarded based on a combination of technical defence effectiveness, incident response speed, strategic communication, and resilience against disinformation. While the organizers deliberately presented the top‑performing teams in no particular order to emphasize collaborative success over competition, the three highest‑scoring joint teams were identified as France and Sweden; Latvia and Singapore; and a quartet comprising Germany, Austria, Luxembourg, and Switzerland. These results illustrate how varied national strengths—ranging from advanced threat‑hunting capabilities to robust legal‑policy frameworks—can combine to create formidable cyber defence units.
Leadership Insights: Detecting and Responding to Threats
Tõnis Saar, Director of the NATO CCDCOE, praised the participants for demonstrating strong capabilities in detecting and responding to malicious activity throughout the exercise. He noted that the high fidelity of the simulated attacks allowed teams to practice real‑world situational awareness, threat intelligence sharing, and rapid mitigation tactics. Saar also stressed a critical lesson: the insights gleaned from Locked Shields must be translated into tangible improvements in national cyber defence postures, policies, and training programmes, especially as adversaries continue to refine their tactics.
Emphasis on Collaboration and Shared Understanding
Exercise Director Dan Ungureanu reiterated that the core objective of Locked Shields extends beyond technical proficiency. He highlighted the event’s role in fostering international collaboration, building mutual trust among allied cyber forces, and developing a shared lexicon and understanding of cyberspace resilience. Ungureanu argued that when nations train together, they not only improve their individual defences but also create a foundation for swift, coordinated action during actual incidents—a factor that has proven invaluable in past real‑world cyber crises.
Historical Evolution: From Modest Beginnings to Global Scale
Locked Shields has undergone remarkable growth since its inaugural edition in 2010, when only four nations and roughly 60 individuals participated. Over the past sixteen years, the exercise has expanded incrementally, incorporating more sophisticated attack scenarios, a broader array of critical infrastructure sectors, and an increasing number of multinational teams. The 2026 iteration reflects this trajectory, showcasing how a modest NATO‑initiated pilot has matured into a cornerstone of global cyber defence preparedness, symbolizing the alliance’s adaptability to emerging threats.
Related Developments and NATO Initiatives
The news brief accompanying the Locked Shields summary referenced several related events that underscore NATO’s broader cyber security agenda. Over 370 organizations participated in GridEx VIII, a North American grid security exercise focused on protecting electricity infrastructure. Additionally, Apple’s iPhone and iPad devices have received clearance for classified NATO use, indicating growing trust in commercial technology for defence purposes. A separate report warned that artificial intelligence can now autonomously hack cloud systems with minimal oversight, highlighting the dual‑use nature of AI in cyber operations.
Implications of AI in Cyber Defence and Attack
Both Tõnis Saar and the related AI warning article pointed to the accelerating influence of artificial intelligence on the cyber battlefield. On the defensive side, AI‑driven anomaly detection, automated threat hunting, and predictive analytics are becoming integral to modern security operations centres. Conversely, adversaries are leveraging AI to generate highly convincing phishing content, automate vulnerability discovery, and execute adaptive attacks that can evade traditional signature‑based defenses. Locked Shields 2026’s scenarios likely incorporated AI‑enhanced attack vectors, compelling participants to experiment with counter‑AI tactics, such as behavioural analytics and human‑in‑the‑loop oversight, to maintain resilience.
Future Outlook and Continued Relevance
As cyber threats grow in frequency, sophistication, and geopolitical relevance, exercises like Locked Shields remain indispensable for maintaining a credible deterrent and ensuring rapid recovery capabilities. The exercise’s emphasis on multinational cooperation, realistic hybrid threat simulation, and lessons‑learned translation aligns with NATO’s broader strategic objectives of enhancing collective defence and preserving technological edge. Moving forward, organizers are expected to further integrate emerging technologies—such as quantum‑resistant cryptography, zero‑trust architectures, and AI‑assisted decision support—into future editions, thereby keeping the drill at the forefront of cyber readiness.
Conclusion
Locked Shields 2026 exemplified the power of large‑scale, collaborative cyber defence training. By uniting over 4,000 experts from 41 nations to defend critical assets against realistic, AI‑augmented attacks while navigating disinformation pressures, the exercise reinforced the necessity of unified action, continuous learning, and adaptive innovation. The strong performance of multinational teams, the endorsements from senior NATO officials, and the evident evolution from a modest 2010 pilot to a truly global endeavour all signal that Locked Shields will continue to play a pivotal role in shaping the resilience of allied cyber forces for years to come.