Spy codes

[dixie1861]

What kind of codes did spies use in the war? I've heard of them using a whole different "alphabet," I guess, of sorts? Were they ever known to just use code words for everything? Did both sides have a certain code that lasted the longest?

Thanks y'all!

 

[BrianB]

Union telegraphers used "route codes" that involved writing the words in a message in a grid, then reading the words back in unpredictable order. For example, a code might start with column three from bottom to top, then column four from top to bottom, then column five and column one in a zigzag pattern, and so forth. Certain critical words were substituted (names of key persons and places, for example, were substituted).

I do not know about spies. Most Civil War spies were so amateurish that they probably did not use a good "code". David O. Dodd, in Arkansas, simply encrypted his message in Morse Code (which merely served to attract attention to it).

 

[major bill]

Freemason cipher the similar Rosicrucian cipher were both know during the Civil War. The Virenere Cipher Tables had been used for centuries. Also invisible ink was used but the most common was probably tiny messages in a hidden spot.

 

[dixie1861]

Oh ok, interesting! Thank y'all! Do you happen to know which side favored which code?

 

[Jimklag]

Book codes were used as well. They were in use long before the Civil War. George Washington's spies used book codes during the Revolution. Buy multiple copies of the same book and use a key to send and decipher page number, row and word from the book. Unless your cryptanalysts know the book being used and have a copy of the same edition, the code is as unbreakable as a one-time pad.

 

[John Hartwell]

An excellent discussion of Civil War codes: https://opinionator.blogs.nytimes.com/2013/03/14/the-codes-of-war/

 

[Cavalry Charger]

An excellent discussion of Civil War codes: https://opinionator.blogs.nytimes.com/2013/03/14/the-codes-of-war/

This is an excellent article.

 

[dixie1861]

An excellent discussion of Civil War codes: https://opinionator.blogs.nytimes.com/2013/03/14/the-codes-of-war/

Oh thank you so much! That looks very good.

 

[dixie1861]

Book codes were used as well. They were in use long before the Civil War. George Washington's spies used book codes during the Revolution. Buy multiple copies of the same book and use a key to send and decipher page number, row and word from the book. Unless your cryptanalysts know the book being used and have a copy of the same edition, the code is as unbreakable as a one-time pad.

Interesting! Thanks!