Behind the Enigma The Authorized History of GCHQ, Britain’s Secret Cyber-Intelligence Agency

For a hundred years GCHQ--Government Communications Headquarters--has been at the forefront of British secret statecraft. Born out of the need to support military operations in the First World War, and fought over ever since, today it is the UK's biggest intelligence, security and cyber agency and a powerful tool of the British state. Based on unprecedented access to documents in GCHQ's archive, many of them hitherto classified, this is the first book to authoritatively explain the entire history of one of the world's most potent intelligence agencies