The impact of ‘Tempest’ on Anglo-American communications security and intelligence, 1943–1970

Abstract

This article examines the impact of the discovery by Britain and the United States in the late 1940s/early 1950s that cipher machines produced compromising emissions, a phenomenon which became known as Tempest. The British and Americans were forced to develop security measures to protect their encrypted communications but the Soviet Union was still able to exploit Tempest emissions from cipher machines in Western embassies in Moscow and read their diplomatic traffic. At the same time, Tempest became an important new way for the NSA and GCHQ to gather communications intelligence, particularly from developing world states and NATO allies.