January 2006
Intermediate to advanced
213 pages
8h 39m
English
JAMES R. CHILES
[Editor's Note: This article, published in the Smithsonian magazine of June 1987, is republished with the permission of the author.]
Toward the end of World War I, the British Army began manufacturing thousands of small cipher machines, "Pletts Cryptographs," for use by the Allied forces. The British asked the American forces to use them as well. No one in the French, British, or American military had been able to break the ciphers; the machine had a mechanism that regularly altered the ciphering scheme, so the first a might be turned into an f and the next a into an r.
Just to be sure that it was safe from enemy codebreakers, the American military passed it on to a remarkable husband-and-wife ...
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