Ireland partakes in the world’s largest ‘live-fire’ cyber defence exercise – ‘Locked Shields’
- Foilsithe:
- An t-eolas is déanaí: 9 Bealtaine 2025
Ireland’s involvement led by the NCSC (National Cyber Security Centre), with support from the Irish Defence Forces
Ireland has again taken part the world’s largest ‘live-fire’ cyber defence exercise, ‘Locked Shields’, organised by the Collaborative Cyber Defence Centre of Excellence (CCDCOE) in Tallinn, Estonia. This year sees the exercise celebrate its 15th anniversary, demonstrating its ongoing development as a pre-eminent global cyber defence exercise.
A joint Irish/US/Bulgarian/Greek team of nearly 220 personnel took part in the week-long event, which allowed them to test their abilities to protect cyber-physical systems in a real-time crisis environment, as well as undertaking strategic exercises in both the legal and communication spheres. The exercise saw the NCSC (National Cyber Security Centre) host staff from the USA and Bulgaria, with Irish staff also present in US Cyber Command.
Ireland’s involvement is led by the NCSC, with support from the Irish Defence Forces as well as private technology companies and academia. This collaborative approach was instrumental in merging public sector oversight with private sector and academic innovation and expertise.
Scope of ‘Locked Shields’
Locked Shields focuses on realistic scenarios, cutting-edge technologies, complex networks, and diverse attack methods. This year’s iteration of the exercise introduces several new elements, including cloud-based infrastructure, surprise technical scenarios requiring rapid adaptation, and an upgraded scoring system with more targeted feedback.
The teams taking part took on the role of national cyber rapid reaction teams that are deployed to assist a fictional country in handling a large-scale cyber incident, with all its implications. In 2025, the organisers increased the number of virtual systems to defend to over 8,000 systems that will be subject to over 8,000 cyber-attacks.
In addition to securing complex IT systems, the participating teams must also be effective in reporting incidents and solving forensic, legal, media and information warfare challenges. The exercise not only tests the technical and operational response to cyber-attacks, but also includes elements of strategic communications, senior public policy decision making as well as whole-of-government and society coordination.
Speaking after the exercise, NCSC Director Richard Browne stated:
“Our core mission is to protect the State against risks in the cyber domain. We know from hard earned experience that we face precisely the same risks and threats as our peers in this exercise. Locked Shields gives us an opportunity to train, practice and compete with and against our peers and partners, and in doing so to test our own skills, capabilities and procedures. To be able to defend the infrastructure, services and data that people in this country rely on, we need to be certain that we remain competitive in this environment, and to continually test ourselves against the best in the world.
“Our success has not come overnight, but reflects years of hard work in training and building capability. Also, cyber-security is a team sport; this exercise and the huge amount of organisation and preparation that goes into preparing for it are hugely useful in building and testing relationships with our colleagues in the Defence Forces and across the range of private companies who have offered their expertise and time to the effort.”
Acknowledging the successful co-operation between the NCSC and the Defence Forces, Brigadier General Brian Cleary, Commander of the Joint Cyber Defence Command remarked:
“Building on our previous participation in Exercise Locked Shields, this year's exercise marks an important step forward for the Defence Forces in strengthening Ireland’s national cyber defence, through close collaboration with the National Cyber Security Centre. Working side by side in one of the world’s most advanced cyber defence exercises, we are enhancing our joint readiness, deepening inter-agency cooperation and underscoring our commitment to collective security and the protection of critical national infrastructure.”
Significant private sector support ensured the successful completion of 2025’s exercise, with contributions from Microsoft Ireland, BAE, ESB, Edgescan, Wiretrap, EY, KPMG, Threatscape, Fortinet, Segura, Flutter Entertainment, and Synopsys.
ENDS
Notes to the Editor
An NCSC representative is available for interview on the subject of taking part in this exercise.
Requests should be sent to the press office in the Department of the Environment , Climate and Communications (press.office@decc.gov.ie or 087-6937580).
Locked Shields
Locked Shields has been run since 2010. It is the largest and most complex international live-fire cyber defence exercise in the world. The goal of this one-of-a-kind cyber and strategic exercise is to provide a realistic and challenging training experience and to field-test cyber resilience, cooperation and chain of command in a stressful environment.
The exercise is run by the Estonia-based NATO Co-operative Cyber Defence Centre of Excellence (CCDCOE), a NATO-accredited knowledge hub located in Tallinn, Estonia, offering a unique interdisciplinary approach to the most relevant issues in cyber defence.
Ireland is one of seven non-NATO members which are contributing participants in the CCDCOE. Locked Shields takes the form of a Red team versus Blue Team exercise, whereby there are real attackers attacking real computer systems.
The fictional Locked Shields scenario consistently reflects contemporary global challenges, integrating geopolitical tensions such as the construction of artificial islands, breaches of international borders, violations of state sovereignty, and, naturally, large-scale cyber-attacks.
The Locked Shields 2025 scenario continues to evolve against the backdrop of the conflict between the fictional island nations of Berylia and Crimsonia, long-standing regional adversaries. Following the storyline developed in previous editions of CCDCOE's Locked Shields and Crossed Swords exercises, Berylia strives to defend its sovereignty against Crimsonian aggression and reclaim its lost territory.
New in Locked Shields 2025, the scenario expands geographically to simulate collaboration across the Atlantic and Pacific theatres. Alongside Berylia and Crimsonia, new fictional nations have been introduced: Revalia and Netoria in the North Atlantic region, and Nekelonia and Selenoa in the Pacific. Notably, Netoria is depicted as a member of both NATO and the European Union.
An NCSC representative is available for interview on the subject of taking part in this exercise; requests should be sent to the DECC press office (press.office@decc.gov.ie or 087-6937580).