Much like the notion of a
Tiger Team, Red Teaming involves getting together a group of people to act and think like "
the enemy". In the world of security this means having a team that
brainstorms new ways to attack possible vulnerabilities.
Red Teaming can involve actual attempts at penetrate security to merely thinking up ways an
aggressor might launch an attack and preparing a report. For a long time the Soviets used a form of Red Teaming in its political/military planning with the USA. The Soviets had a policy that if they thought of it, America probably had too and was actually planning for it.
The term likely comes from the American Air Force's use of "
Red Flag" pilots who are trained to fly, live, and think like
Soviet pilots.