Was the Navajo code ever discovered?

The Navajo code was created using Navajo as a base to a alphabet substitution code in 1942 by Philip Johnston and the original 29 Navajo code talkers. He was the son of a missioonary and had grow up on the Navajo reservation.

The Japanese never broke the code. About 400 of the 540 of the Navajo who served in the Marines in WWII were code talkers. The code even could not be broken by Navajos who were captured and tortured by the Japanese. Hr said after the war to one of the code talkers; "I never figured out what you guys who got me into all that trouble were saying."

It was used in the Pacific war, in the Occupation of Japan and in the Korean War. It was declassified in 1968. They could not receive recognition until after that.