220px-ChoctawCoders

Choctaw soldiers in training in World War I for coded radio and telephone transmissions

Code talkers are people in the 20th century who used obscure languages as a means of secret communication during wartime. The term is now usually associated with the United States soldiers during the world wars who used their knowledge of Native American languages as a basis to transmit coded messages. Read more:  https://en.wikipedia.org/wiki/Code_talker