Describe Philip Johnson's role in the Navajo Code Talker organization in World War II

Military communications have to be coded to keep them secret from the enemy. However the process of coding and decoding are time consuming processes. Furthermore the codes may be broken by the enemy. Nations have devoted considerable effort trying to create unbreakable codes. In World War II both Germany and Japan thought they had such unbreakable codes, but in fact these codes were broken and their most vital information were readily available to their enemies.