NAVAJO CODE TALKERS, WINDTALKER THE KEY OF MARINES IN PACIFIC

Guadalcanal, Tarawa, Peleliu, Iwo Jima: the Navajo code talkers took part in every assault the U.S. Marines conducted in the Pacific from 1942 to 1945. They served in all six Marine divisions, Marine Raider battalions and Marine parachute units, transmitting messages by telephone and radio in their native language — a code that the Japanese never broke.

The idea to use Navajo for secure communications came from Philip Johnston, the son of a missionary to the Navajos and one of the few non-Navajos who spoke their language fluently. Johnston, reared on the Navajo reservation, was a World War I veteran who knew of the military's search for a code that would withstand all attempts to decipher it. He also knew that Native American languages — notably Choctaw — had been used in World War I to encode messages.

Johnston believed Navajo answered the military requirement for an undecipherable code because Navajo is an unwritten language of extreme complexity. Its syntax and tonal qualities, not to mention dialects, make it unintelligible to anyone without extensive exposure and training. It has no alphabet or symbols, and is spoken only on the Navajo lands of the American Southwest. One estimate indicates that less than 30 non-Navajos, none of them Japanese, could understand the language at the outbreak of World War II.

For other information, check this out at :

http://www.californiaindianeducation.org/native_american_veterans/navajo_code_talkers.html

Below there are some navajo's code that used in WW2 (DECLASSIFIED UNDER DEPARTMENT OF DEFENSE DIRECTIVE 5200.9). ...

NAMES OF VARIOUS
ORGANIZATIONS    NAVAJO WORD                LITERAL TRANSLATION
CORPS            DIN-NEH-IH                 CLAN
DIVISION         ASHIH-HI                   SALT
REGIMENT         TABAHA                     EDGE WATER
BATTALION        TACHEENE                   RED SOIL
COMPANY          NAKIA                      MEXICAN
PLATOON          HAS-CLISH-NIH              MUD
SECTION          YO-IH                      BEADS
SQUAD            DEBEH-LI-ZINI              BLACK SHEEP

OFFICERS
COMMANDING GEN.  BIH-KEH-HE (G)             WAR CHIEF
MAJOR GEN.       SO-NA-KIH                  TWO STAR
BRIGADIER GEN.   SO-A-LA-IH                 ONE STAR
COLONEL          ATSAH-BESH-LE-GAI          SILVER EAGLE
LT. COLONEL      CHE-CHIL-BE-TAH-BESH-LEGAI SILVER OAK LEAF
MAJOR            CHE-CHIL-BE-TAH-OLA        GOLD OAK LEAF
CAPTAIN          BESH-LEGAI-NAH-KIH         TWO SILVER BARS
LIEUTENANT       BESH-LEGAI-A-LAH-IH        ONE SILVER BAR
COMMANDING OFFICER HASH-KAY-GI-NA-TAH       WAR CHIEF
EXECUTIVE OFFICER  BIH-DA-HOL-NEHI          THOSE IN CHARGE

source : http://www.history.navy.mil/faqs/faq61-4.htm