Altogether some 800 people from 25 countries are taking part in the exercise, Locked Shields 2017, which began on April 24 and will run through the 28th, spokespeople for the CCD COE said. This year, the scale of the exercise as well as the number of technologies, networks and devices involved will be significantly bigger than in previous years.

"The Locked Shields exercise is more complicated, bigger and more intense this year than ever before," CCD COE chief Sven Sakkov said. "The new level is necessary to offer a challenges worthy of the improving skills of the teams of the 19 participating countries and NATO. In addition to many new technological elements, a strategic play will take place at the same time as the classic technical exercise in which policy advisers can practice decision-making processes in the framework of solving cyber incidents."

According to the scenario of the exercise, Team Blue must ensure the functioning and principal services of the military base of a fictitious country at a time when its electrical networks, drones, command structures and other systems come under attack. The scenario suggests that at least 2,500 attacks will be carried out.

Even though the main aim of the exercise is to perfect the participants' technical skills, a strategic component will be added this year to offer training opportunities also to political and legal experts.

CCD COE has staged Locked Shields exercises annually since 2010.

The contributors to the 2017 edition of the exercise are the defense forces of Estonia, Finland and Sweden, the British Armed Forces, U.S. European Command and Tallinn University of Technology. Siemens AG, Threod Systems, Cyber Test Systems, Clarified Security, Iptron, Bytelife, BHC Laboratory, openvpn.net, Guardtime and several other businesse are also participating in the event.