This year's edition of the exercise embraces both a technical and a strategic game, the main aim of which is to rehearse protecting different vital services and military systems in the event of a large-scale cyberattack. Altogether more than 1,000 experts from 30 countries are taking part in the exercise, spokespeople for the the CCD COE said.

"Exercise Locked Shields demonstrates how large-scale cyber incidents affect very different systems and areas, both in the civilian and military domain. An international cyber conflict has multiple layers, which extend beyond cyberspace. In addition to solving technical challenges, it is important to understand the impact of cyber operations on the strategic and political level. That's what we are rehearsing at the exercise," said CCD COE director Merle Maigre.

Only the countries which are members of the CCD COE or its key partners can take part in the exercise with a team protecting the system, or Blue Team. In this year's exercise 22 Blue Teams are taking part, including teams of NATO and the European Union.

"Locked Shields is highly valued among cyber experts. Access to this exercise is one of the reasons why countries wish to become members of the CCD COE," Maigre said.

In the intensive exercise that uses state-of-the-art technologies, computer networks and methods of attack, cyber security, legal, strategy and media experts from the participating countries, NATO and the EU get the opportunity to put their skills in solving a cyber incident to a test.

Aare Reintam, the head of the exercise at the CCD COE, said that in light of the cyber threats that have been identified of late, participants in this year's exercise are being offered the opportunity to rehearse protecting various vital services, civilian and military systems. In accordance with the scenario of the exercise, participants must be able to protect the system against cyberattacks targeting the power grid, 4G public safety networks, a water purification station and control systems of military drones, Reintam said.

In Locked Shields 2018, the teams will be protecting the computer systems and information systems of an imaginary country that has come under attack. In addition to a large-scale cyberattack, a number of other developments undermining security will take place in the country under attack. The aim is to offer a real life-like picture of the scope of the impact that cyber incidents can have and how well thought-out comprehensive must be the measures aimed at solving them.

The CCD COE is a NATO-accredited cyber defense hub focusing on research, training and exercises. The international military organization based in Estonia is a community of currently 20 nations providing a 360-degree look at cyber defense, with expertise in the areas of technology, strategy, operations and law.

The CCD COE is home of the Tallinn Manual 2.0, the most comprehensive guide on how international law applies to cyber operations. The center also organizes the world's largest and most complex international live-fire cyber defense exercise, Locked Shields.

Another highlight of the center is the International Conference on Cyber Conflict (CyCon) a unique event joining key experts and decision-makers of the global cyber defense community in Tallinn every spring. The tenth anniversary event, CyCon X: Maximizing Effects, will take place from May 30-June 1. In partnership with the Munich Security Conference, the CCD COE will host the Cyber Security Summit in Tallinn on May 29, on the eve of CyCon.

The CCD COE is staffed and financed by its member nations, which currently include Austria, Belgium, the Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, the Netherlands, Poland, Portugal, Slovakia, Spain, Sweden, Turkey, the United Kingdom and the United States.

Australia, Norway and Japan have all recently announced that they are planning on joining the CCD COE.