Code Girls: The Untold Story of the American Women Code Breakers of World War II

by Liza Mundy

WAVES had a song written as a counterpoint to “Anchors Aweigh”: WAVES of the Navy, There’s a ship sailing down the bay. And she won’t slip into port again Until that Victory Day. Carry on for that gallant ship And for every hero brave Who will find ashore, his man-sized chore Was done by a Navy WAVE.

During services the men would sing the original and the women would sing the descant, and the harmony was so moving and powerful that Frances Lynd, from Bryn Mawr’s class of 1943, always said it made the hair stand up on the back of her neck.

When the women graduated, they received their uniforms, with bars to show they were ensigns. Their beloved Mildred McAfee might feel she was struggling against the Navy brass—which she was—but the women felt that they belonged to the U.S. Navy.

The night before departing, they lined up to receive their uniforms. Goucher’s Fran Steen, training at Mount Holyoke, was asked her size and said that she was a four. She was given a fourteen—the only size left—and would have it tailored later. Her skirt hung down to her instep and her new warm thick navy wool coat flapped around her ankles. On the train ride back, some children thought the women were nuns.

It took a while for the women to master the regulations of appearing in public. Edith Reynolds, rushing to catch a train in Grand Central Terminal, crossed in front of a male officer. Remembering she had been taught never to walk in front of a superior officer without saying “by your leave,” she blurted it out and saw from the astonished way that he looked at her that he thought she was trying to pick him up.

The U.S. Navy’s basic requirements for female officers were a college degree or two years of college plus two years of work. Regular enlisted women, who made up the bulk of WAVES recruits, could get by with a high school degree. This opened up opportunity to women who had not had the advantage of college. Once again, more women than expected answered the call: While naval officials had anticipated there might be ten thousand WAVES in total, by the time all was said and done, more than one hundred thousand women would serve. Women joined up for all sorts of reasons—because they didn’t have any brothers and wanted to represent their family in the war effort; because they did have brothers and wanted to bring them home.

At the outset there was a cap on the number of officers, so women were often overqualified for their ranks. Many college women enlisted as ordinary seamen, just to get in.

Sometimes WAVES were confronted by mothers unhappy that their sons were being sent into combat, thanks to the women coming in to work in the desk jobs. But others thought the WAVES were wonderful and would invite them home for milk and cookies or holiday meals. The Navy was sensitive to what was being said about its women. The fine print said an enlisted member of the WAVES had to be at least five feet tall and weigh ninety-five pounds. It also stated that she had to be a woman of “good conduct.”

Many got the sense that the Navy had some unwritten criteria regarding looks.

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Jane Case was the daughter of Theodore Case, a physicist whose own contributions to communications technology—he pioneered sound in movies and worked during World War I to develop the Navy’s ship-to-shore communications—had made him a wealthy man. Jane grew up in a huge house in Auburn, New York, where she had been crushingly lonely. Her mother was insecure and belittled Jane, making her conscious of her imperfections, such as highlighting her nearsightedness by snatching the glasses off her face. Jane, to her relief, was sent away to the Chapin School on the Upper East Side of New York City. While she loved it there, she hated Manhattan high society. It was stuffy and boring, and elite boys at their boarding schools would lazily throw darts at women’s dance invitations to determine which they would accept.

Armed Marines inspected the women’s badges and bags. Many of the Marines had seen traumatic duty at places like Guadalcanal and were given the guard job as a recuperative assignment. When she went in and out, Anne Barus made a point of looking the men in the eye as they saluted her. She had a brother in the Pacific and she knew the Marines had been through hell. The enlisted women were given a naval rating, Specialist Q, which was inscribed on a patch. The Q did not stand for anything, but it did arouse a lot of curiosity.

There was periodic unrest in the city, and in the country, as civil rights advocates pushed to advance social changes that were taking place as a result of the war. In 1944, Eleanor Roosevelt and WAVES director Mildred McAfee managed to gain entry for African American women into the WAVES. But there would be no racial experimenting at the stodgy and sometimes paranoid Naval Annex, where top officers considered any newcomer—anybody with an unorthodox background—to be a security risk. In a June 1945 memo, Commander J. N. Wenger wrote that he had explored the “question of employment of colored WAVES at Naval Communications Annex” and felt integrating the code-breaking unit would be too risky. He concluded that it would be “unwise to conduct an experiment of such serious implications” in a unit where security was so important, and ventured that “there are many other activities in the Navy where experiments of this sort can be carried on without so much danger in the event that difficulties arise.” Black WAVES would have to take their patriotism, their intellect, and their talent elsewhere,

In late 1943, Wellesley’s Bea Norton, now married, became pregnant and notified her superiors. “Horrified, they gave me three days to get out of uniform and told me I could consider it a discharge with honor.” Her boss, Frank Raven, was furious at the rule and begged her to come back as a civilian, but she was too tired and angry, and she resigned in December.

Together the code breakers were able to reconstruct Yamamoto’s precise itinerary, which called for a day of hops between Japanese bases in the Solomon Islands and New Britain. Their translation concluded that the commander would “depart RR (Rabaul) at 0600 in a medium attack plane escorted by six fighters; arrive RXZ (Ballale) at 0800”; depart at 1100 and land at RXP (Buin) at 1110; leave there at 1400 and return to Rabaul at 1540, traveling by plane and, at one point, minesweeper. He would be conducting an inspection tour and visiting the sick and wounded. It was an extraordinary moment. The Americans knew exactly where the enemy’s most valuable—and irreplaceable—naval commander would be, and when. Yamamoto was known for punctuality. Far above the pay grade of those working additive recovery, Nimitz and other top war officials decided Yamamoto would be shot down. It was not a light decision, assassinating an enemy commander, but they made it. The itinerary, as one memo later put it, signed the admiral’s “death warrant.”

Not being military, Dot and Crow couldn’t take the long train journeys the Navy women did; or, if they wanted to, they would have to pay full fare and risk not getting a seat. The military enjoyed fare discounts and seating priority. Even so, the two friends managed to find plenty to occupy their rare free time. They went window-shopping downtown and perfected the art of looking dressy with very little money. Dot managed to acquire a silver fox stole. They toured the museums and monuments and visited the National Cathedral, which was still under construction, but awe-inspiring even so.

Back at the apartment, Crow’s sister Louise—aka Sister—had a tendency toward melancholy, and Dot decided to cheer her up by throwing a party for everybody living in Fillmore Gardens, a gesture that resulted in the young women’s being invited to reciprocal soirees in the apartments of neighbors, who were mostly young couples.

As they went about their travels, Dot would make tart observations about people, like, “She goes to church too much,” and Crow would laugh and say, “Dot, you are an original.” Dot was an entertainer and Crow was an appreciative audience. They were entirely unalike, and entirely bonded. At Christmas, on their modest salary, Crow gave Dot a tiny pair of gold earrings. Dot felt closer to Crow in some ways than to her own siblings.

Ann Caracristi came to work at Arlington Hall each day wearing bobby socks, flat shoes, and a pleated skirt that billowed and swung. She looked like a bobby-soxer, the kind of carefree and heedless college girl who lived for boyfriends and swing dances. But appearances were deceiving. What hidden depths Ann Caracristi had. What capabilities. General Douglas MacArthur did not know it, but his secret weapon—or one of them—was this affable and somewhat cosseted twenty-three-year-old from the upper middle classes of exurban Bronxville, New York. Intellectually ferocious, Annie worked twelve-hour shifts, day after day. The only time she missed work for any time at all was when she came down with chicken pox. She phoned apologetically to say in a tiny, pitiful voice that she could not come in.

Though she had been an English major in college, she possessed the mind of an engineer. It was fascinating for Wilma Berryman—the West Virginia schoolteacher who had been one of William Friedman’s early Munitions Building hires, now supervising a major unit at Arlington Hall—to see what Annie could do.

So gifted was she that Wilma made Ann the head of her research group. At Arlington Hall, to have a recently graduated female in charge of a key unit was not unusual. It was normal. Unlike the Navy operation, the Army’s code-breaking operation at Arlington Hall was polyglot, open-minded, and nonhierarchical.

Tiny Jo Palumbo, daughter of an Italian immigrant laborer, was the person who swore in newcomers, and the sight of her administering the grave secrecy oath had inspired one code breaker to write a lyrical poem in her honor. Unlike the Navy, Arlington Hall also had an African American code-breaking unit. This was not so much because the place was unusually liberal-minded, but rather because Eleanor Roosevelt—or somebody at the top—had declared that 12 to 15 percent of the Arlington Hall workforce should be black. It was poor recompense for the fact that many of Arlington’s black residents had been pushed out of their homes by the construction of the Pentagon and other military edifices, but work was welcome and this was better than nothing. Arlington Hall’s African American workers had to take segregated transport to get there, and many, even those who were college graduates, were given menial jobs as janitors and messengers. But there also was a special code-breaking unit whose existence was unknown to many of the white workers.

Despite its segregated school system and the inequality of resources that accompanied segregation, the city of Washington had a number of highly regarded black public schools, as well as Howard, one of the country’s premier historically black universities. One of the team members, Annie Briggs, started out as a secretary and rose to head the production unit. Another, Ethel Just, led the expert translators. The team was led by a black man, William Coffee, who studied English at Knoxville College in Tennessee, started out as a janitor and waiter at Arlington Hall, and rose to this position.

In short, in its eclecticism and, often, its eccentricity, the atmosphere at Arlington Hall was unlike anything the U.S. military had ever produced.

To a striking degree, Arlington Hall was what would nowadays be called a “flat” organization, an egalitarian work culture in which good ideas could emerge from any quarter and be taken seriously. In part this was thanks to the open-mindedness of the people in charge, but it was also thanks to their desperation.

To break a complex enciphered code like the ones used by the Japanese military, it’s essential to have what’s known as “depth”: lots and lots of intercepted messages that can be lined up and compared. In the panicked atmosphere after Pearl Harbor, the group made a stab at a solution nonetheless. In 1941, a British colleague brought some Japanese Army intercepts to Friedman’s operation in the old Munitions Building. Friedman shut four of his staffers—Solomon Kullback, Wilma Berryman, Delia Taylor, and Abraham Sinkov—in a room, telling them not to emerge until they had broken something. The job was just too big. After about three months, Solomon Kullback stood up and shoved his desk back into the German section. “I’ve had it,” he said. The only positive outcome was that Delia Taylor and Abe Sinkov fell in love, got married, and moved into a houseboat at the wharf.

After its stunning victories in the first half of 1942, the Japanese Army began to spread out. Millions more troops now occupied a greatly enlarged amount of territory. Japanese units fanned out over Asia and the Pacific archipelagos: China, Hong Kong, the Philippines, Thailand, Burma, Malaya, the Dutch East Indies. The Eighth Area Army concentrated around the stronghold of Rabaul, on the island of New Britain. Each unit remained tied to its home base in Japan and was obliged to send back reports on things like casualties and the need for reinforcements. As the Japanese Army got farther from Japan, radiomen increased the power of their transmissions, and this made it much more feasible to intercept them.

“Visualize, if you will, the entire communications set-up of the Japanese military forces, with many thousands of men whose entire existence centered around the preparation and transmission of messages,” Lewis later wrote, “and then contrast that huge organization with the small group of technicians at our own establishment.”

The Japanese devised a host of minor codes and at least four major four-digit systems: one for ground forces, another for air forces, another for high-level administrators, and another for the “water transport organization,” which was a vital lifeline of marus, or commercial merchant ships, commandeered by the military to carry resources, including oil, food, and equipment. Each system was identified by a discriminant—an unenciphered four-digit code group at the beginning. It was a huge tangle, and as of January 1943 there were just fifteen American civilians, twenty-three officers, and twenty-eight enlisted men working on breaking all of them.

They had caught a small break, though. When a Japanese plane crashed in Burma, the British captured some message templates—a template is a blank form with some code groups filled in to speed the process—and sent them to Arlington Hall, which had them in its possession by late January 1943. Wilma and Ann began having quiet conversations about how best to use this material. They agreed that chaining differences was “silly” and that it made more sense to use the templates and the bits of information they contained. They had a couple of other tools as well. They had received a report from Australia with some names and ID numbers for Japanese Army units in the southwest Pacific. In addition, the U.S. Navy had sent over some cribs.

The Arlington Hall address team had well-kept records, and Wilma Berryman remembered some Japanese Army messages with addresses that might be the same as these Navy ones. She found them and began fiddling around, writing the plain words from the Navy address codes below the Army ciphers. “I sort of remembered having seen something in that file and I went back to the file and found it,” was how she put it later. “I found what I thought looked like it ought to be that, the same thing. I had it on my desk and I just wasn’t positive.” Suddenly she noticed one of the men who worked with their unit, Al Small, standing behind her. He stood there for a while, watching. “Wilma, what are you doing?” Small asked. She showed him how she was lining up the Army messages against the Navy cribs. It seemed to be working. The captured message blanks gave her the underlying code group, and the Navy crib provided its likely meaning.

The problem with enciphered codes is that they do not yield to immediate solution like machine ciphers do. Even after a basic understanding is achieved, there remains a great deal of work. The code breakers had to build a bank of additives and figure out what each code group stood for. It had taken Agnes Driscoll and her team years to master the Imperial Japanese Navy code systems, but the Arlington Hall team did not have years.

Like the Japanese Navy, the Japanese Army cryptographers were fond of sum checks as a guard against garble, but they had devised a method different from the “divisible by three” sum check of the Japanese Navy. In this system, the code breakers discovered, the four-digit code groups were actually three digits, plus a fourth digit that served as a sum check. If a code group was 0987, for example, 098 was the actual code group, and 7 (using false math) was the sum check: 0 + 9 + 8 = 7. Reconstructing an enemy codebook is called “book-breaking,” and Ann Caracristi, working with the linguists, turned out to be stunningly good at it. By summer 1943, they knew that 1113 stood for shibucho, 1292 for taichoo, 1405 for butai, and 3957 for bukkan. They dug out the code groups for Hiroshima, Singapore, Kupang, and Tokyo.

The work that Ann Caracristi and Wilma Berryman were doing enabled U.S. military intelligence to construct what is called the order of battle: an accounting of the strength, equipment, kind, location, and disposition of Japanese Army troops. They were able to pinpoint where the enemy was quartered and headed. Soon “MacArthur’s headquarters had as good a picture of the Japanese military set-up as he had of his own,” as Solomon Kullback put it.

Morale might have been high among the elite code breakers whom Ann Caracristi hung out with, but among the rank and file at Arlington Hall Station, complaints included everything from whirring fans to coworkers snapping gum. Bad insulation, unpleasant bosses, tablemates who smoked and lollygagged—all these were grounds for bitter complaint. It was the first time many of the women had spent time in a bona fide workplace—apart from a classroom—and they discovered what workplaces are and have been since the dawn of time: places where one is annoyed and thwarted and underpaid and interrupted and underappreciated.

The perennially discontented William Seaman seems to have been pushed around by a clique of what would now be called mean girls. “When I came into our section it was controlled by a small group of young girls, who made it difficult for new men by assigning us disagreeable jobs and by preventing us from learning how to do the more technical work. They are not in control now, but it is generally known that they pass judgment on new people and are responsible for some being transferred.” Food! Orders! Window blinds! Men! Women! Coworkers! Young people! It was a cascade of standard workplace discontent.

There were vocabulary words associated with sailing schedules. According to training materials compiled at Arlington Hall, atesaki was “destination” or “address”; chaku was “arriving”; dai ichi was “first”; honjitsu was “today.” Maru was “commercial ship”; sempakutu was “ship”; sempakutai was “convoy unit”; teihaku was “anchoring”; yori was “from”; yotei was “schedule.” Gunkan was “warship.” Chu was “now.” Hatsusen was “ship leaving.” Hi was “day”; hongetsu was “this month”; senghu was “onboard ship”; shuzensen was “ship being repaired”; tosai sen was “ship loading.” Dot’s workday consisted of messages that, once deciphered, said things like “PALAU DENDAI/ 2/ 43/ T.B./ TRANSPORT/ 918/ (/878/)/ 20th/ 18/ JI/ CHAKU/ ATESAKI/ DAVAO/ SEMPAKUTAI/ 4/ CEBU/ E.T./” If it sounds hard and exhausting, it was.

At first, the 2468 system was enciphered by false math, but in February 1944, a few months after both Dot and Crow arrived, the Japanese began using squares. As the Japanese coped with their changing island situation, the ex-schoolteachers had to cope with Japanese cryptanalytic changes.

This meant breaking a thousand messages a day. In August 1944, the Japanese began using a new additive, new codebooks, a new square, and new indicator patterns. Staying abreast of these was Crow’s department. Crow with her math skills had been assigned to the “research unit,” which did the ongoing analysis that enabled Dot to do the active processing work. Dot didn’t know that, nor did Crow.

The women in Department K—Dot’s unit—were a “very fine group,” according to one Lieutenant Bradley, an Army officer who rotated into the unit late in 1943. He was there when a break into a new square led to “great glee over the entire place.” He watched as dozens of new recruits joined and became adept. At first, readers needed overlaps that were ten or fifteen messages deep to recover code groups, but they soon needed fewer and fewer. “The pattern was the main thing,” said Lieutenant Bradley. “There was no information service or cribbing section at that time. Each reader had to depend on what he could remember.” The women knew they were performing well. “The great value of the intelligence derived from the [2468] messages is a constant incentive to the department,” a report noted, praising Dot’s Department K, which was producing all kinds of shipping intelligence, foretelling what units were about to receive oil or gasoline; what ships were in a given harbor; what convoys were getting ready to sail and where they were headed.

Joe Richard, the young officer working in the Australian unit who spotted the telltale digit pattern that led to the break in 2468, told later of how the recovery of a codebook on Okinawa, in June 1945, gave them all the translations for that period and “led to reading about the Japanese army’s preparations to fight against any landing on their home islands. These were so extensive, involving every Japanese, that the Allied general staff estimated (based on experience at Iwo Jima and Okinawa) that 1 million casualties might be expected by our allied forces, which I think induced Truman to use the atom bomb and to moderate FDR’s unconditional surrender ultimatum and accept Japanese surrender keeping the Emperor.”

Even from her distant vantage point, Dot could tell that things were going much better for the Allies in the Pacific, thanks in part to the efforts of women like her and Crow and even Miriam.

She and the other women knew that ship sinkings were the logical and desired consequence of their concerted efforts. They did not feel remorse. America was at war with Japan; Japan had started the war; the lives of American men were at stake, not to mention America itself. It really was that simple.

Dot’s unit was completely run by women, and she took pride in the work they did. She liked it much better than teaching school.

Beginning in 1943, starvation became the common lot of the Japanese soldier. Officials later estimated that two-thirds of Japanese military deaths were the result of starvation or lack of medical supplies. Broken messages revealed the extent of the devastation. One message described how a group of Japanese soldiers were making a ten-day supply of rice last for twenty-five days. “By resorting to chewing it raw instead of cooking it,” the message said, “the period of consumption had been prolonged somewhat.”

They boarded the train at midnight, leaving Washington under sealed orders. The women knew only that they were headed “west.” The train departing the capital was an ordinary troop train—dirty, crowded—with no sleeping berths. The women slept sitting up, if they slept at all, and three who were unable to find seats took turns resting in a cubbyhole used by the brakeman. Some cherished the hope that they were being sent to California. But when the train arrived at their destination, it emerged that “west” didn’t mean quite what they thought. They were in another Union Station, this one in Dayton, Ohio. The women gathered their things and made their way into the chill morning air, where they mustered for roll call.

The women were billeted at a place called Sugar Camp, a thirty-one-acre property named for the magnificent maple trees on the grounds. For much of its history the state of Ohio was agrarian, and the trees at one time had been tapped for maple syrup. Dayton had been transformed during the War of 1812, when it served as a mobilization point for American attacks on Canada and British troops in the northwest U.S., bringing banks, businesses, and factories. This continued during the Civil War, when it served as a supplier for the Union Army. The city nurtured more than its fair share of inventors and entrepreneurs, including not only Orville and Wilbur Wright, the aviation pioneers, who had their bicycle shop here, but also Charles Kettering, who invented the automobile ignition system. Kettering’s self-starter was the reason Dayton had a General Motors plant. It also had Dayton Electric; the headquarters of Frigidaire; and Wright Field, used for aviation and testing.

Around the country, major companies like Ford, IBM, Kodak, Bethlehem Steel, Martin Aircraft, and General Motors were cooperating with the war effort, producing weapons and war materiel and helping develop systems. So were universities like Harvard and MIT. NCR was fully committed: One hundred percent of its operations were war-related work. Seeing as how there was nothing, just now, for the salesmen to sell, Sugar Camp had been turned over to the Navy women, six hundred in all.

The women labored seven days a week, twenty-four hours a day, in shifts. Three times a day, more than a hundred of them would muster at Sugar Camp and march four abreast into Dayton, up hills and down, in snow and rain and sunshine, passing a house where a girl they called Little Julie would come to her window and wave at them. Before long, people in Dayton were saying you could set your clock by the sight of the WAVES marching.