contexts: 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 service members during the world wars who used their knowledge of Native American languages as a basis to transmit coded messages . In particular , there were approximately 400 -- 500 Native Americans in the United States Marine Corps whose primary job was the transmission of secret tactical messages . Code talkers transmitted these messages over military telephone or radio communications nets using formal or informally developed codes built upon their native languages . Their service improved the speed of encryption of communications at both ends in front line operations during World War II .
name: Code talker
answers.input_text: short
answers.span_text: Native Americans in the United States Marine Corps whose primary job was the transmission of secret tactical messages
questions.input_text: who were the code talkers and what did they do