The Navajo language was very quick. Unlike the Mose code, which took hours, Navajos could handle a message in minutes (Hawthorne). They made their words short and quick so that the message was quick and accurate ("The Code Talkers"). When they received a message, they would write it down in English and de-code it. This was the perfect way to communicate without anyone eavesdropping!
history.sandiego.edu