The Full Wiki

More info on World War I cryptography

World War I cryptography: Wikis


Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.


From Wikipedia, the free encyclopedia

Codes and ciphers were used extensively in World War I. The decoding by British Naval intelligence of the Zimmermann telegram helped bring the United States into the war.

Trench codes were used by field armies of most of the combatants (Americans, British, French, German) in World War I.



British decrypting was carried out in Room 40 by the Royal Navy and in MI1 by British Military (Army) Intelligence.


  • Ernst Fetterlein was in the Tzarist Russian Ministry of Foreign Affairs from 1896, and solved (among others) German, Austrian and British codes. He was eventually made chief cryptographer with the rank of Admiral. With the Russian Revolution in 1917 he fled to Britain, and was recruited to Room 40 in June 1918 to work on Austrian, Bolshevik and Georgian codes.
  • The Russians used an overly complicated version of the Vigenère Cipher. It was broken within three days by Austro-Hungarian cryptanalyst Hermann Pokorny.


The French Army employed Georges Painvin, and Étienne Bazeries who came out of retirement, on German ciphers .

Germany and Austria

Germany and Austria intercepted Russian radio traffic, although German success at the Battle of Tannenberg (1914) was due to interception of messages between the Russian commanders in the clear!

The ADFGX and ADFGVX field ciphers were a modified polybius system with single order double columnar transposition and frequent key change, with letters optimized for Morse. It was later broken by the famous French cryptanalyst Georges Painvin.


Most American cryptography in World War I was done at the Riverbank Laboratory where Elizebeth Friedman, William F. Friedman and Agnes Meyer Driscoll worked. The Riverbank Laboratory, Chicago was privately owned by Colonel George Fabyan.

Herbert Yardley began as a code clerk in the State Department, and was with the American Expeditionary Force in World War I as a Signals Corps cryptologic officer in France. He later headed the Black Chamber (MI-8), a new cryptanalysis group started in 1919, immediately after World War I, and funded jointly by the State Department and the US Army.

The US Navy cryptanalysis group, OP-20-G, was also started after World War I (in 1922).

See also



Got something to say? Make a comment.
Your name
Your email address