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The Stager Cipher

  • Page ID
    11564
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    The Stager Cipher

    Secret Codes in the Civil War

     

    Secret codes were an important part of the Civil War, especially for the Union forces who fought most of the war on enemy ground. Though telegraph lines were supposed to allow people to send private messages to each other, it was easy to tap the wires and listen in.

    To make sure important messages were not learned by the enemy, they were coded using a complicated system known as the Stager ciphers, the code keys known only by a handful of people.

    Anson Stager (1825-1885) was the first general manager of Western Union Telegraph Company. The company, formed in 1856, had only been in business five years when the Civil War broke out.

    When the Confederacy fired on Fort Sumpter April 12, 1861, Stager, whose office was in Ohio, was asked by the state's governor to devise a code so he could use the telegraph to keep in touch with nearby states.

    In 1862, realizing the telegraph could be very useful for the war effort, President Abraham Lincoln took over the nation's new telegraph companies and turned them into a nation-wide system under military control.

    Though Stager had no interest in codes, he proved to have an amazing skill at them. His simple code, and later variations of it, could not be broken by the Confederate forces throughout the war.

    Stager's code soon brought him to the attention of Secretary of War Edwin Stanton, who placed him in charge of the newly-formed U.S. Army Signal Corps in 1863. His ciphers became the nation's first military cryptography system.

    The Stager ciphers use two ways of encoding a message.

    First, important words such as place names and proper names and times were replaced with code words. In one code, "A. Lincoln" was replaced with "Adrian;" "the enemy" was replaced with "village."

    Second, the messages were coded using what is known today as a "route cipher." After the message had been coded, the words were placed in a grid, and blanks in the grid were filled in with meaningless words.

    A code book let the encoder and decoder know which order to place the words based on their positions in the grid.

    During the war, Stager came up with 12 different code systems, each like the other but varied slightly, using different replacement words and different paths to encode.

    Confederate code breakers eventually discovered how the messages were coded, but without a key they could not break the code. Copies of Stager-coded messages were even placed in Confederate newspapers in the hopes they could be broken, but with no luck.

    E.P. Alexander, the founder of the Confederate Army Signal Corps, once said that the Stager system was an excellent code with one weakness: the possibility that the code books needed to code and decipher the messages might one day fall into enemy hands.

    Among the R.H. Milroy Collection at the Jasper County Library are a few messages the General received during his days on the battlefield, coded using the Stager ciphers.