Tempora is the codeword for a formerly-secret computer system that is used by the British Government Communications Headquarters (GCHQ). This system is used to buffer most Internet communications that are extracted from fibre-optic cables, so these can be processed and searched at a later time. It was tested from 2008 and became operational in late 2011.

Government Communications Headquarters (GCHQ) is an intelligence and security organisation responsible for providing signals intelligence (SIGINT) and information assurance (IA) to the government and armed forces of the United Kingdom. Primarily based at "The Doughnut" in the suburbs of Cheltenham, GCHQ is the responsibility of the country's Secretary of State for Foreign and Commonwealth Affairs, but it is not a part of the Foreign Office and its Director ranks as a Permanent Secretary.