Codebreakers and Foreign Offices: The French, British and American Experience

Abstract

LIKE other major foreign ministries, the Quai d’Orsay, the Foreign and Commonwealth Office and the State Department nowadays receive much of their most valuable intelligence from cryptanalysts: from the Groupement des Contrôles Radio-électriques in France, from the Government Communications Headquarters in Britain, and from the National Security Agency in the United States. The historical origins of these three secret agencies are very different. In France there is an almost continuous history of diplomatic codebreaking stretching back to the cabinet noir founded by Cardinal Richelieu. In Britain the Foreign Office inherited an official ‘decypherer on its foundation in 1782 but abolished the post in 1844 and abandoned codebreaking altogether for the next seventy years. The United States lived in a state of cryptographic innocence until its entry into the First World War prompted the creation of its first ‘Black Chamber’ (so named in honour of the French original). Despite these national differences, however, there are three striking similarities in the twentieth-century experience of diplomatic codebreaking in France, Britain and the United States.