Cryptographic properties Code talker

navajo code talkers, saipan, june 1944

non-speakers find extremely difficult accurately distinguish unfamiliar sounds used in these languages. additionally, speaker has acquired language during childhood sounds distinctly different person acquired same language in later life, reducing chance of successful impostors sending false messages.

navajo attractive choice code use because few people outside navajo had learned speak language. virtually no books in navajo had been published. outside of language, navajo spoken code not complex cryptographic standards. have been broken if native speaker , trained cryptographers have worked effectively. japanese had opportunity attempt when captured joe kieyoomia in philippines in 1942 during bataan death march. kieyoomia, navajo sergeant in u.s. army, not code talker, ordered interpret radio messages later in war. however, since kieyoomia had not participated in code training, messages made no sense him. when reported not understand messages, captors tortured him. japanese imperial army , navy never cracked spoken code.