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

EnigmaKingdom was attempting to join the European EconomicCommunity (EEC) or Common Market, which in 1993would become the European Union. France was attemptingto keep Great Britain out of the EEC, and the buggingsimply revealed that the French were not going to budge,without revealing any likely means of inducing them to doso. Wright, who also led Stockade, later recalled that theoperation “was a graphic illustration of the limitations ofintelligence.”❚ FURTHER READING:BOOKS:Aldrich, Richard J. The Hidden Hand: Britain, America, andCold War Secret Intelligence. Woodstock, NY: OverlookPress, 2002.Epstein, Leon D. British Politics in the Suez Crisis. Urbana:University of Illinois Press, 1964.Kelly, Saul, and Anthony Gorst. Whitehall and the SuezCrisis. Portland, OR: Frank Cass, 2000.Louis, William Roger, and Roger Owen. Suez 1956: TheCrisis and Its Consequences. New York: Oxford UniversityPress, 1989.West, Nigel. The Circus: MI5 Operations 1945–1972. NewYork: Stein and Day, 1983.Wright, Peter. Spycatcher: The Candid Autobiography of aSenior Intelligence Officer. New York: Viking, 1987.SEE ALSOCipher MachinesEgypt, Intelligence and SecurityMI5 (British Security Service)Special Relationship: Technology Sharing Between theIntelligence Agencies of the United States and UnitedKingdomUnited Kingdom, Intelligence and SecurityENIAC Machine.SEE Ultra, Operation.❚ LARRY GILMANEnigmaEnigma was a ciphering (code communication) systemused by the German military from 1926 until the end ofWorld War II, and by several other nations for some yearsafter. Enigma was the first mechanized message-encryptionsystem to see wide use. Enigma produced such thoroughlyscrambled messages that for many years its cipherEncyclopedia of Espionage, Intelligence, and Securitywas considered unbreakable both by the German militaryand its foes. Polish and British mathematicians, however,cracked the Enigma cipher in time to give the Allies accessto most German military communications throughoutWorld War II. The German government never knew thatthe Enigma cipher had been broken and that its militarycommunications were often transparent, giving a significantadvantage to the Allies on many occasions. TheJapanese military also used a cipher related to Enigmaduring World War II. The Japanese version of Enigma wascracked by American cryptographers, providing a crucialadvantage to the Allies in the Pacific theater. U.S. knowledgeof secrete Japanese transmissions was essential, forexample, to victory at the crucial battle at Midway, theJapanese navy’s first major defeat in several centuries.Many military strategists and historians hold that Alliedsuccess in cracking the Enigma and related ciphers helpedsignificantly shorten World War II.Origin of Enigma. During World War I, cumbersome paperand-pencilciphers were still the rule, as they had been forcenturies past. (A cipher is any scheme for transformingordinary written language—plaintext—into a coded, butapparently random string of characters, ciphertext.) AfterWorld War I, several inventors turned their attention to themechanization of ciphering, seeking to increase accuracy,speed, and security. The most successful of these inventorswas German engineer Arthur Scherbius, who in 1918,created a cipher machine he named the Enigma. (This isnot a translation; the word “enigma” is the same in Germanand English). Scherbius was unsuccessful in sellingEnigma to commercial buyers. It was not until 1923 thatEnigma was chosen by the German government as itsstandard ciphering system, as Germany had only justlearned how much damage had been done by the breakingof its ciphers by the Allies in World War I. Between1925 and 1945, the German military bought over 30,000Enigma machines, deploying slightly different systems toits European armies, its army in North Africa, its air force,and its navy.The Enigma cipher. The Enigma cipher is built upon thesimplest of all cipher types, the substitution cipher. In asubstitution cipher, one letter of the alphabet is substituteddirectly for another. A substitution cipher for a sixletteralphabet might appear as:Plaintext:Ciphertext:A B C D E FF C A B D EUsing this cipher, the plaintext word BAD (for example)would produce the ciphertext word CFB. Such ciphersare easy to implement, but also contain easily brokencode, as their ciphertext contains all the regularities of405