Blue teams from around the world gathered in Estonia for Locked Shields 2018.

Security experts from NATO have been declared the winners of this year’s Locked Shields competition – the largest and most complex international live-fire cyber exercise.

The event, which took place in Estonia last week, saw 22 blue teams from around the world fight to keep more than 150 complex IT systems up and running in a real-time defense exercise involving more than 2,500 attacks.

The participants were tasked with protecting a fictional country, Berylia, which was being subject to coordinated cyber-attacks causing disruptions to the electric power grid, 4G public safety networks, drone operation, and other critical infrastructure components.

In addition to maintaining the systems, the blue teams had to be efficient in reporting incidents, executing strategic decisions and solving forensic, legal, and media challenges.

After “excelling in all categories” of the exercise, the NATO team took the top spot this year, followed by teams from France and the Czech Republic.

“Every single participating team deserves credit for handling the complex cyber challenges of Locked Shields,” said Aare Reintam, project manager of technical exercises at NATO’s Cooperative Cyber Defense Centre of Excellence (CCDCOE), which organized the event.