ENCYCLOPEDIA OF Espionage, Intelligence, and Security Volume ...

Bletchley ParkThe Duke of York, foreground, reads a printout from the Colossus computer during his tour of Bletchley Park, the former British Spy Center, England.©CORBIS SYGMA.begin all transmissions. Exploiting these two weaknesses,British cryptologists unraveled the Enigma code mathematicallyin late 1940.Even though cryptologists could read portions ofEnigma transmissions, they encountered the same delayof accessing intercepted information as they had withother codes. Another bombe was constructed that couldprocess Enigma codes, expediting code breaking. However,cryptologists and engineers at Bletchley Park realizedthat another mechanical solution was needed to fullyexploit German intercepts. To this end, two Bletchley Parkengineers invented Colossus, the first electronic, programmablemachine in 1943. Colossus not only decodedmessages, but also broke through the overlaying cipher,producing a ready to translate copy of the intercept in theoriginal German. With Colossus, Bletchley Park coulddecipher German communications before the intendedrecipients. Translated intercepts were immediately passedon to intelligence and military officials, making BletchleyPark central to the Allied war effort.Security at Bletchley Park. Concerned that the Germanmilitary and government would change encryption devisesif they knew of the operation, operations at BletchleyPark were shrouded in absolute secrecy. Details of OperationUltra and other specific code breaking missions werefully known by only four people. A special intelligenceprotocol was established to funnel information into andout of Bletchley Park. No one link in the chain of informationknew more than two other people involved in theoperation.In order to guard Bletchley Park secrets in the event ofa German invasion or bombing campaign of Britain, BletchleyPark’s extensive archives of every decoded interceptand the accompanying original intercept were photographedand catalogued at the Bodleian Library at OxfordUniversity. Code breaking equipment was supposed to beentirely disassembled, put on a nearby train to Liverpool,and then ferried to the United States if Bletchley Park werein danger of falling into enemy hands. The tight securitysurrounding Bletchley Park was remarkably successful.The operation was one of the few government and militaryoutposts that was not compromised by German spies.Legacy of Bletchley Park. The work of cryptologists andengineers at Bletchley Park is often credited with shorteningthe duration of the war in Europe by an estimated twoto three years. Bletchley Park intelligence aided military132 Encyclopedia of Espionage, Intelligence, and Security