Locked Shields 2023 marks the world’s largest NATO cybersecurity exercise, launched in Estonia to test defense readiness across public and private networks. This event is coordinated by the NATO Cyber Defense Centre of Excellence in Tallinn, a hub that brings together cyber professionals from multiple allied nations. The exercise showcases a sustained effort to strengthen national and international capabilities in defending digital infrastructure against escalating cyber threats.
According to the CCDCOE press office, more than 3,000 participants from 38 countries are involved in Locked Shields 2023. The scale of participation reflects a broad commitment to building practical, real world responses to cyber incidents that could disrupt essential services and government operations.
During the exercise, teams focus on shielding government IT systems and critical infrastructure, including energy networks, water utilities, transport networks, and public safety operations. The objective is to demonstrate practical resilience under pressure, with teams working to maintain continuity of services even as simulated attacks intensify in both frequency and sophistication as the scenario unfolds.
Leading the initiative, CCDCOE director Martha Noorma explained that the exercise is designed to mirror a deteriorating security environment where major cyber incursions threaten daily life. The scenario emphasizes how rapidly attackers can disrupt power grids, water treatment facilities, and other essential public services, underscoring the need for robust incident response and recovery processes.
Participants will show how effectively IT systems can stay online and recover quickly from disruption, even when time is scarce and decision making is critical. The exercise brings together military and civilian entities to test interagency coordination, information sharing, and rapid decision making under stress, creating a platform for shared learning and improvements in defense posture across the alliance.
In addition to Estonia, the Locked Shields event serves as a learning laboratory for NATO allies and partner nations to validate new defensive tools, cyber range capabilities, and incident command procedures. The exercise highlights the ongoing emphasis on resilience and collaboration as cornerstones of national security in the digital age.
Last autumn, senior NATO leadership signaled continued focus on cyber defense with announcements that future exercises would expand in scope and complexity. The overarching goal remains clear: better preparing governments to prevent, detect, and respond to sophisticated cyber threats, with a strong emphasis on protecting critical infrastructure and public safety networks in North America and beyond. The coordination between allied cyber defense centers, incident response teams, and civilian agencies remains a defining strength of Locked Shields and similar initiatives, reinforcing shared security commitments across the alliance.