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

Border Crossing and InspectionJapanese codes and could adapt Enigma bombe designsto fit Japanese Red and Purple codes.How a bombe worked: The mechanics of code breaking. TheEnigma teleprinter functioned by replacing plain text letterswith random letters, chosen by the settings of a seriesof rotors individual to each letter and space in a plain textmessage. The Enigma machine had a possible 15 million,million (15 x 10 12 ) combinations, but within each rotor set,the combinations were far fewer. Repeated phrases, called“cribs,” such as common greetings or the name and ranksof officers, gave cryptographers a clue about the mathematicalcycle of the rotors and how they replaced plaintext letters. Once a series of these cycles was mathematicallydetermined, the logic equation could be used topainstakingly decipher intercepts. The bombe worked onthe concept that these cycles, and the equations representingthem, could be replaced with electrical circuits.The Turing Bombe replicated the rotors of a GermanEnigma machine, replacing the center reflecting rotor witha standard rotor that could be handset. The rotors wereconnected by a set of 26 parallel wires. The wire selectedby the rotor positions determined the passage of voltageto the plug board. The machine then searched for variouscombinations of loops and live wires, assigning each avalue on the plaintext/ cipher text rows of a diagonalboard. A teleprinter decoded the messages on to synchronizedpaper tapes.Legacy of bombes. By the end of the war, the bombe wasstill being used to decode enemy intercepts in the UnitedStates. British code breakers and engineers at BletchleyPark, however, invented a new machine, Colossus, thatdecoded messages more rapidly and with greater accuracythan the bombes. Colossus was the world’s firstprogrammable computer, capable of decoding and transcribingmessages without the cumbersome synchronizationof paper tapes. The advent of punch-card computerprocessing ended the era of the code breaking bombe.After the end of the war, British intelligence dismantledits operations as Bletchley Park. The numerous bombes,and Colossus, were disassembled or destroyed. The entirecode breaking operation remained secret until thelate-1980s, but after the news of Bletchley Park operationswas broken to the public, historical preservationists soughtto restore Bletchley Park and its code breaking apparati.The British Computer Society’s Computer ConservationSociety embarked on an ambitious endeavor to reconstructColossus and the Turning bombe in 1999.❚ FURTHER READING:BOOKS:Hinsley, F. H. British Intelligence in the Second World War.Cambridge: Cambridge University Press, 1988.Hinsley, F. H. and Alan Stripp, eds. Codebreakers: TheInside Story of Bletchley Park. Oxford: Oxford UniversityPress, 2001.Stinson, Douglas. Cryptography: Theory and Practice, secondedition. Chapman and Hall, 2002.SEE ALSOCodes and CiphersCodes, Fast and Scalable Scientific ComputationColossus IFISH (German Geheimschreiber Cipher Machine)Operation MagicOSS (United States Office of Strategic Services)Poland, Intelligence and SecurityPurple MachineUltra, OperationUnited Kingdom, Intelligence and SecurityWorld War II, United States Breaking of Japanese NavalCodesBorder Crossing and Inspection.SEE IBIS (Interagency Border Inspection System).Bosnia and Herzegovina,Intelligence and SecurityFollowing World War I, the nations in the Balkan regionwere unified into a single state, known after 1929 asYugoslavia. Tensions between the region’s ethnic populationsremained high, but the establishment of a dictatorshipunder Marshal Tito kept Yugoslavia united after WorldWar II. After Tito’s death, authoritarianism continued todominate the Yugoslavian regime. The Yugoslavian intelligencecommunity was dominated by secret police forcesand government-backed political espionage. Modeled afterintelligence and security forces in the Soviet Union,Yugoslav intelligence focused on protecting the rulingregime under the direct control of the Communist CentralCommittee.In the early 1990s, Yugoslavia broke apart followingthe fall of the Soviet Union. In 1991 and 1992, the variousethnic states in the Balkan region declared their independence.Border disputes and ethnic tensions flared in theregion, sparking intense warfare. The most intense conflicterupted in Bosnia and Herzegovina. The state wasdeeply divided. Bosniak Muslims, seeking autonomy,fought Serbian-backed forces. As the conflict escalated,the international community became concerned with theregion’s endemic warfare. By the time United Nations andNATO forces intervened in the region, ethnic cleansing—genocide—plagued Bosnia and Herzegovina.138 Encyclopedia of Espionage, Intelligence, and Security