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

Cryptology, HistoryA Korean War veteran examines a display explaining how cryptology was used to intercept North Korean radio transmissions during the Korean War at theNational Cryptologic Museum in Ft. Meade, Maryland. AP/WIDE WORLD PHOTOS.The Twentieth CenturyIn the early twentieth century, another invention, the radio,had a profound effect on cryptography by greatlyimproving the capacity of senders to transmit messagesto remote areas. World War I marked a watershed incryptography. Not only was it the first major conflict inwhich radio was used, it was the last in which a greatpower failed to employ cryptographic communications.On the Eastern Front, the Russians sent uncoded messagesthat were easily interpreted by Russian-speakingintelligence officers on the German and Austrian side,leading to a massive victory for the Central Powers atTannenberg in 1914.The war also marked the debut of the Germans’ADFGX cipher, which was so sophisticated that Frenchcryptanalysts only deciphered it for one day, after whichthe Germans again changed the key. But the cryptographicdimension of the war did not belong entirely to the CentralPowers. British signal intelligence cracked the Germancipher, and intercepted a message from German foreignminister Arthur Zimmermann to the Mexican president,promising to return territories Mexico had lost to the290 Encyclopedia of Espionage, Intelligence, and Security