Navajo Code Talkers

Overview
The Navajo Code Talkers created the only unbreakable code in modern military history. From Guadalcanal to Iwo Jima and Okinawa, the Code Talkers served with distinction in every major engagement of the Pacific Theater from 1942 to 1945. Their code, which the Japanese never managed to break, helped to end World War II and save thousands of lives.

The Code Talkers were young Navajo men who were tapped by the U.S. Marines to devise a code for radio communications. The Code Talkers' cryptographic innovation made use of a little-studied and extremely complex Native American language unlike any other. English words were spelled out using Navajo words to represent letters of the English alphabet. For instance, the words "wol-la-chee" (which means "ant" in Navajo) and "be-la-sana" (apple) both stood for the letter "A." The developers of the code also used Navajo words to represent more than 400 frequently used military terms. The word "da-he-tih-hi" (hummingbird) stood for "fighter plane," and "chay-da-gahi" (tortoise) was translated as "submarine."

Source

 * U.S. National Intelligence: An Overview 2011, at 14.