Cryptology during World War I

1. Cryptology during World War I

2. Arthur Zimmermann • Received his doctorate of law • Took up a career in diplomacy • Rose to rank of consul • Became under Secretary of State • German Foreign Minister

3. Secret telegram • Proposed a German alliance with Mexico • Intercepted and decrypted by the British Government • Forced the United States into WWI Zimmermann Telegram

4. ADFGVX Cipher • First cipher used by the German Army near the end of WWI • Extension of the earlier cipher called ADFGX by Colonel Fritz Nebel • Fractioning transposition cipher that used a Polybius square with a single columnar transposition • Uses 36 letter alphabet (26 letters and 10 digits) • Broken by French cryptanalyst Lt. Georges Painvin

5. The Enigma • Designed by Arthur Scherbius • Allowed businesses to communicate confidential documents • Consisted of many rotors turning on a common axis • These rotors are marked with numbers 1-26 or letter A-Z

6. Germans began to use trench codes, which evolved into enciphered code • After the Americans joined the battle, they adopted them as well Trench Codes • Used by the French, German, and U.S. troops • Used trench-raiding parties to sneak into enemy lines to try and snatch codebooks.

7. American Cryptography • Done at the Riverbank Laboratory • Most influential people who worked there: Elizebeth Friedman William F. Friedman Agnes Meyer Driscoll • German success at Battle of Tannenberg

8. Room 40 • Sir Alfred Ewing put a group together for Britain’s cryptology bureau • Initially operated out of Ewing’s office, but as they became more productive they moved into Room 40 of the Admiralty Old Building • Group intercepted a telegram sent by the Germans