Not a cipher — a language. 420 Navajo Marines. Never compromised in wartime.
The Navajo Code Talkers transmitted battlefield messages in 20 seconds that took machines hours to encode. Their unbroken code helped secure every major Marine assault in the Pacific — and was kept classified for 23 years after the war.
This exhibit honors the 420 Navajo Marines who served as Code Talkers during World War II. Their service, classified for 23 years after the war ended, saved countless lives across the Pacific Theater. This is not just a cryptography story — it is a story about people and sacrifice.
Philip Johnston, a civil engineer and son of a missionary who had grown up on the Navajo reservation, proposed using the Navajo language as a battlefield code to the US Marine Corps in 1942. The Marines were skeptical but tested it: messages that took hours to encode and decode mechanically were transmitted in 20 seconds.
The 1st Marine Division deployed the first 29 Navajo Code Talkers at Guadalcanal. By the end of WWII, 420 Navajo Marines had served as Code Talkers across the Pacific. Major Howard Connor, 5th Marine Division signal officer at Iwo Jima, said: "Were it not for the Navajos, the Marines would never have taken Iwo Jima."
The program was classified until 1968. The Code Talkers received the Congressional Gold Medal in 2001.
Military terms were assigned Navajo words by meaning — creating a codebook that existed only in the memories of the Code Talkers themselves:
Military terms → Navajo words by meaning: Fighter plane = da-he-tih-hi "hummingbird" Bomber = jay-sho "buzzard" Submarine = besh-lo "iron fish" Destroyer = ca-lo "shark" Battleship = lo-tso "whale" General = bih-keh-he "war chief" Colonel = atsah-besh-le-gai "silver eagle" America = ne-he-mah "our mother"
For words without Navajo equivalents, a phonetic alphabet was used:
Phonetic alphabet:
A = wol-la-chee (ant)
B = shush (bear)
C = moasi (cat)
K = klizzie (goat)
T = tha-ah (turkey)
"ATTACK" = wol-la-chee, tha-ah, tha-ah,
wol-la-chee, moasi, klizzie
It wasn't. No Navajo Code transmission was ever decrypted by Japanese forces during WWII. The code was rendered obsolete not by cryptanalysis but by the end of the war. It was declassified in 1968 — 23 years after the last transmission.
The code's security rested on multiple layers of impenetrability:
| Concept from Navajo Code | Modern Evolution |
|---|---|
| Security through linguistic complexity | Security through mathematical complexity — AES relies on unsolved mathematical problems |
| Shared knowledge as the key | Pre-shared keys (PSK): both parties must possess the same secret before communication |
| Unwritable key (living language) | Out-of-band key exchange: some secrets must be established through a channel the attacker cannot observe |
| Never broken — exposed by declassification | Cryptographic systems are eventually declassified, not broken — forward secrecy ensures past traffic stays safe |
A short Navajo Code message. Use what you just learned.
Hint: Each Navajo word = one letter. A=ant, T=turkey, C=cat, K=goat
Never broken — no Rosetta Stone, no attack surface.
| Exhibit | 35 of 37 |
| Era | WWII · 1942–1945 |
| Security | Never Broken |
| People | 420 Navajo Marines |
| Year | 1942–1945 |
| Broken By | Never |