During the wars of the 20th century, cryptography came to determine the destiny, not just of nations, but of the globe. We offer you three examples, one from the First World War and two from the Second. Both wars began in Europe, with the entry of the United States following sometime afterward.

The Zimmerman telegram

By early 1917, the First World War had been raging on the continent of Europe for two and a half years, but the U.S. was officially neutral. The question on everyone’s mind was whether the U.S. would enter the war, and if so, when. On January 16, 1917, the German Foreign Secretary (equivalent to the American Secretary of State), Arthur Zimmerman, sent a ciphered telegram to the German ambassador to Mexico. The British intelligence services intercepted the telegram, which consisted of hundreds of groups of digits, each group up to 5 digits long (“13042 13401 8501 115” and so forth). The British had captured some German code books that described an earlier version of the cipher and so were able to decode the message.

The Zimmerman telegram described a plot in which the Germans would begin “unrestricted submarine warfare” on February 1. If America entered the war, Germany proposed to help Mexico reconquer territories in Texas, New Mexico, and Arizona from the U.S.! A way was found to leak this telegram to the U.S. government without revealing that the British had broken the German cipher. The telegram’s message was printed in American newspapers on March 1, 1917, and the U.S. entered the war just over a month later. The entry of the U.S. decisively tipped the balance of power in the war away from Germany. The deciphering of the Zimmerman telegram thus changed the course of history.

The Enigma code

In the Second World War, German U-boats were destroying a large fraction of the Allied shipping in the Atlantic Ocean. The Germans used a coding machine, code-named the Enigma, which used a collection of cipher wheels and switches to apply a different cipher to every single letter of a message. The British applied an immense amount of effort to breaking this code, which they finally did. The breaking of the Enigma code turned the tide of the war in the Atlantic and made the D-Day invasion that much more possible.

The Navajo code talkers

In the Pacific theater of the Second World War, the American armed forces used Native American speakers of the Navajo language. The Navajo code talkers used words from the natural world to represent military objects: different types of birds were different types of aircraft, different types of fish were different types of ships, and so on. The Navajo code talkers were used to communicate among different American military units, with great success. After the war, it was revealed that the Japanese had broken several American codes but had made no progress with breaking Navajo. Much of the American success in the Pacific theater can be attributed to the contribution of the Navajo code talkers.

Uncovering Masonic Codes and Ciphers