Locked Shields 2025, organised by the NATO Cooperative Cyber Defence Centre of Excellence, brought together 41 nations committed to defending cyberspace – and this week, that coalition proved its strength in action. As cyber threats grow in scale and complexity, so has Locked Shields. What began as a small-scale test of capabilities has, over 15 years, evolved into the most complex cyber defence exercise spanning military, civilian, legal, and strategic domains.
New technologies, challenges, and collaborative mechanisms are introduced each year to reflect the constantly shifting cyber landscape. In 2025, new features included a cloud-based infrastructure, quantum computing injects, AI-driven narratives, and a redesigned scoring system rewarding collaboration and resilience.
“In today’s environment, where cyberattacks can disrupt entire societies, our defence must be united, agile, and always evolving,” said Mart Noorma, Director of the NATO CCDCOE. “Locked Shields is held in a competitive environment, but it’s true strength lies in cooperation. It brings together nations to learn, adapt, and grow, side by side, because that’s how resilience is built.”
This week, more than 4000 people from 41 nations in 17 multinational Blue Teams were challenged to protect virtualised national systems – from power grids and battle management systems to satellite links and 5G networks. At the same time, they were tested on legal assessment, communication, disinformation, forensics, and national-level decision-making under pressure.
Locked Shields, organised by the NATO CCDCOE, has always been more than just a competition. While scoring helps measure and motivate performance, the ultimate goal remains shared: to build stronger, smarter, and more collaborative cyber defence across borders.
The three highest-scoring teams of Locked Shields 2025 are:
- Team of Germany and Singapore
- Team of Poland and France
- Team of Italy, Slovenia, United States (Colorado National Guard)
“I want to thank every Blue Team member, every organiser, and every partner who made this exercise possible,” said Dan Ungureanu, Exercise Director of Locked Shields 2025. “Locked Shields is made real by the people behind it. Your effort helps shape the future of collective cyber defence.”
As we wrap up this year’s edition, the work does not end. The planning for the next Locked Shields has already begun – driven by the evolving threat landscape, the momentum of collaboration, and the commitment of our cyber defenders to keep pushing boundaries together.
“Cyberattacks have become increasingly complex and extensive over the years, and Locked Shields has followed the same path. It is a great recognition of Estonia’s cyber capabilities that all this takes place right here in Tallinn,” concluded Estonian Minister of Defence Hanno Pevkur.
Locked Shields is made possible in partnership with numerous industry and academic partners: Accenture, Arctic Security, ATECH, AWS, BHC, Bittium, Booz Allen Hamilton, Clarified Security, Conducttr, CR14, Forestall, Fortra, FS-ISAC, HAVELSAN, Helheim Labs, IPS-Intelligence, Microsoft, Mnemonic, Openfactory Group, Palo Alto Networks, Rocket.Chat, SANS, ShellDot, Siemens, Singapore National Cybersecurity Laboratory, Skarleon, Solita, SpaceIT, Telsy and Turku University of Applied Sciences.