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Historical Events
Historical Events | Aug. 20, 2021


As both the Navy's OP-20-G and the Army's Signals Intelligence Service began to solve Japanese cryptosystems in the 1930s, they faced a second challenge, the underlying language itself.

For a variety of linguistic and cultural reasons, the Japanese language has been difficult for westerners to master. A European missionary of the 16th century, one of the first but certainly not the last foreigner to be frustrated by the subtleties of Japanese, called it the "Devil's language." Many Europeans and Americans since have come to agree with him.

Word order in Japanese is more akin to Latin than English, with verbs placed at the end of sentences and suffixes on each word indicating its place in the sentence structure. There are different levels of politeness, used according to the relative social positions of speaker and listener. Verbs assume diverse forms, many in the passive voice to avoid bluntness.

Japanese uses three writing systems. Chinese characters, known as kanji, were taken into Japanese as "loan words" at several points in history and supplement the two indigenous writing systems, known as hiragana and katakana. These latter writing systems are similar to each other, each composed of two-letter syllables. In written messages, code book values might be in any of the three writing systems, kanji, hiragana, or katakana.

Katakana was usually used for sending telegrams and for Morse transmissions from ships or military units -- and was what American intercept operators meant when they said they "copied kana" or "copied kana code."

In order to provide standard representation of Japanese in intercept, OP-20-G's Laurance Safford bought and modified typewriters for intercept operators. This machine came to be called the RIP-5 and eventually was shared with the Army's SIS.

An OP-20-G history described the RIP-5 as "the kana character represented by a dot-dash combination which, in International Morse, represented a Roman letter, was printed by the type block actuated by the key, which on a normal typewriter, caused that letter to print." That is, when a Japanese clerk transmitted "-…," the U.S. operator recognized it as Roman "B" and struck "B" on the RIP-5; the typewriter, however, printed out the kana character represented by "-…" in Japanese.

In the 1920s, the U.S. Navy had surreptitiously photographed a Japanese Navy code book, dubbed the "RED BOOK," because of its cover. A missionary couple, Mr. and Mrs. Emerson Haworth (in some reports, spelled Haaworth) were hired to translate it; Haworth had been a missionary in Japan and had taught at Tokyo University. Their translations were invaluable, but, once the work was completed, a Navy officer had to further render their classical expressions into naval jargon.

In one case, Haworth encountered the Japanese phrase BARU ENDO SUTARODO REINJIFAINDA, and considered it gibberish. A language officer with naval experience recognized it immediately as the "Barr and Stroud Range Finder" taken as a "loan word" directly from English into Japanese.

Diplomatic Japanese had its own difficulties, even for foreigners experienced in the language, since the Foreign Office used a considerable number of idiosyncratic abbreviations and acronyms. For example, the Japanese word for the United States, beikoku, was usually written simply "BKK." American cryptanalysts and translators had to deduce meanings from context and compile their own working aids.

Until almost the outbreak of war, the U.S. Army and Navy maintained programs for "language officers" in Tokyo. In addition to rigorous classroom exercises, the students were immersed in Japanese society and culture for three years. After war began, the Navy operated a Japanese-language school in a number of locations in the United States. A small percentage of the Navy graduates of the pre-war program and the wartime school were taken into OP-20-G for cryptanalytic or translation work.

Edwin Layton, later to be Admiral Nimitz's intelligence officer, went through the language program, starting in 1929. He remembered that the Naval Attaché at the U.S. Embassy in Tokyo told him, "I don't know anything about this language, but I understand it's difficult." The attaché went on to say, "You have only two duties to perform: One, study and master the Japanese language; two, stay out of trouble. If you fail in either, I'll send you home in the next ship." The attaché then warned Layton against any activity that could be construed as espionage, and concluded with, "Payday is once a month. Other than that, I don't want to see you."

The attaché's warning about espionage-like activity reflected acute Japanese sensitivity about American prying. This sensitivity increased in the early 1930s when Herbert Yardley published his book The American Black Chamber, with his revelations about solving Japanese codes in the 1920s, brought every American in Japan under suspicion as a spy.

During his stay in Tokyo, Layton met another Language Officer, Joseph Rochefort, with whom he was to work closely in Hawaii during World War II. He was surprised years later to learn that Rochefort had already spent two years in cryptology in Washington by the time he was a Language Officer.

In 1932, the Chief of Naval Operations recommended that Marine Corps officers who had completed Japanese instruction, be given a course in cryptanalysis.

One Marine Corps officer who received Japanese language training and went into cryptology was Captain Alva B. Lasswell. He was attached to the American Embassy in Tokyo in 1935 for language training, and subsequently assigned to the Marine Barracks in Cavite, the Philippines, in September 1938 as "Assistant War Plans Officer." This title was simply a cover designation for his actual duties as language officer for the cryptanalytic office. His next assignment placed him in charge of the Navy's Shanghai intercept station.

During World War II, Lieutenant Colonel Lasswell, working under Joseph Rochefort, was an important figure in the cryptanalytic successes of Station HYPO, the Navy's COMINT center in Hawaii.

The Army had a smaller number of language officers, therefore a smaller pool of qualified personnel available to work on the solution and exploitation of Japanese cryptosystems from a language standpoint.

When the Signal Intelligence Service was formed in 1930, the first persons hired were required to have foreign language capability as well as skills in mathematics. Frank Rowlett had knowledge of German, Abraham Sinkov of Spanish, and Solomon Kullback of French. None of the mathematicians brought knowledge of the Japanese language into SIS.

Therefore, John Hurt was hired on May 30, 1930 as a "cryptanalyst aide," in reality, a Japanese linguist. Since he knew French as well, Hurt spent time translating classic French-language texts on cryptology for SIS use.

John Hurt had never studied Japanese formally, nor had he lived in Japan -- he had learned the language from a college roommate! Yet, he amazed those who had studied the language in-country with his detailed knowledge of it.

Hurt was the epitome of the absent-minded professor. Solomon Kullback, one of the leading cryptanalyts of the time, remembered him. "There are more stories about John Hurt than you can shake a stick at. There is no question that he had a genius or flair for languages. He was always interested in picking up new words in any language and using them. Unfortunately, sometimes he made a mistake. I think he learned two words in Russian, one which means "good-bye" and one which means "thank you," and got them confused. He met somebody who had a Russian background and they were talking, when they were supposed to leave, instead of saying "thank you," John Hurt says "good-bye." The Russian got a little indignant and went off in a huff….

"He had a theory that when you crossed the street, you just ignored traffic rules and you don't worry about cars. You stared at them, just as you would at an animal. Unfortunately, one time he was nudged, knocked down by a taxicab, and the taxicab man got out, all upset, and runs over to him and says, "Are you hurt?" John gets up and brushes himself off and says, "Yes, John B." and walked off…."

In 1933, teamed with Kullback, Hurt began to work on actual Japanese messages. The traffic was old, not intended for current use, but Hurt spent several years working with different cryptanalysts on old Japanese message texts. This exercise gave him a good grasp of diplomatic-style grammar and vocabulary.

The first current Japanese message translated by Hurt and forwarded to the military for use was in 1935. It dealt with a proposal for a joint Japanese-Mexican fishing operation that might have been a cover for espionage.

Hurt, and later other Japanese linguists, would dictate their translations to a series of stenographers.

While some other SIS personnel dabbled in the Japanese language, John Hurt remained the only full-time translator until mid-1937. As the crisis deepened between the U.S. and Japan, Hurt began to feel extreme pressure in keeping up with the translations, and a second civilian translator was hired. (After World War II, Hurt, who had had bouts of ill health, was placed on indefinite sick leave, which lasted over two years).

One of the unfortunate continuities of Communications Intelligence work has been the woeful lack of qualified linguists. In most crises, including the world war, there were not enough of them at the outset and many did not have the training or experience to be effective COMINT producers.

Nevertheless, just as they acquired brilliant cryptanalysts, the U.S. COMINT organizations hired or trained excellent Japanese linguists in the prewar period, and, as their numbers increased after Pearl Harbor, trained them for wartime service.



  • Captain J. S. Holtwick, Jr., USN (Ret), Naval Security Group History to World War II, June 1971, SHR-355, CCH Files.
  • John Hurt, Some notes on our work from 1930 to 1945, SRH-252, CCH Files.
  • Rear Admiral Edwin Layton, with Captain Roger Pineau and John Costello, And I was There": Pearl Harbor and Midway -- Breaking the Secrets (New York: William Morrow and Company).
  • James McIntire & R. D. Howell, Sr., "U.S. Marine Corps in COMINT," NCVA (Paducah, Ky.: Turner Publishing Company, 1996), pp. 46-50.
  • Larry Myers, "Language Training for War with Japan," NCVA (Paducah, Ky.: Turner Publishing Company, 1996), pp. 35-39.



After war began, SIS began training personnel in Japanese; one of the instructors at Arlington Hall Station was Edwin Reischauer, the son of missionaries, and future ambassador to Japan.