Crossed Swords is an annual technical red teaming cyber exercise training penetration testers, digital forensics experts and situational awareness experts. Over the years Crossed Swords has evolved from a relatively straightforward technical training workshop to an exercise that also involves leadership training for the command element, legal aspects and joint cyber-kinetic operations. The exercise also provides a training opportunity for the members of Red Team playing the adversary in the Locked Shields cyber defence exercise.

The recent iterations of Crossed Swords have been organized jointly by the NATO CCDCOE and CERT.LV.  Since 2018 the exercise has expanded considerably in scope and complexity, covering several geographical areas, involving critical information infrastructure providers and cyber-kinetic engagement of military units. As of 2019, a designated cyber command element is included in the exercise training audience. Crossed Swords 2019 was the largest and most complex exercise in this series so far, with more than 100 experts from 23 countries participating.

NATO CCDCOE has been organising the exercise since 2016. The concept was initiated in 2014, when the first red teaming workshop was conducted. CCDCOE-led exercises and research provide its member nations with a testbed for experimentation in cyber operations. Crossed Swords tests the capabilities and practice skills that participants would need when planning and executing a full-spectrum cyber operation, together with elements from the other domains.