Confederate cipher reel

This is a cipher reel used by the Confederate Army during the Civil War. "The principal cryptosystem used by the Confederate government and military was a centuries-old cipher known variously as the 'court' or 'diplomatic' cipher, now referred to as 'the Vigenere' for its 16th century proponent. In its usual form, an alphabetic square or matrix, comprised of 26 alphabets, each slide over by one letter, is combined with a key (usually a phrase) to produce 'polyalphabetic substitution.' To assist the eye and facilitate use of the cipher, the Confederates manufactured several different types of devices, such as the 'reel.'

This is one of just two such devices known to have survived the Civil War and it bears penciled notations of the names of Confederate officers and soldiers.

Click here to read the related story on the National Cryptologic Museum, and click here to check out the entire Road Trip 2010 package.