Intercept: The Enigma War

Few revelations about the Second World War have aroused so much interest as the fact that Britain was able to read many of the secret communications of the German Armed Forces. Yet the Germans were convinced that Enigma, the enciphering machine they used, was one of their best-kept secrets. In fact, Polish cryptanalysts, with the help of French Intelligence, had unravelled Enigma's mysteries by 1932, constructed some auxiliary devices to make the process of deciphering faster, and handed all these secrets over to the British and French in 1939.

Now, using first-hand material, including documents, personal accounts and interviews, Dr Jozef Garlinski tells the full story of the breaking of the Enigma secret - the use of agents and backroom activity, the war of nerves and the excitement. He goes on to recount the setting up of the Ultra net in 1939, based at Bletchley Park in the English home counties, where a small group of cryptanalysts worked night and day to master the continual modifications made to Enigma by the Germans.

"Intercept" reveals how the information derived from Enigma played a vital role not only in many actions and campaigns, including the Battle of Britain, the Battle of the Atlantic, the war in North Africa and the Allied landing in France, but also in movements of the Soviet Army and in the anti-Hitler conspiracy in Germany. A substantial Appendix explains exactly how Enigma was broken, using mathematical, cryptological and analytic methods.