An American pioneer in the field of cryptology—the study of writing and solving secret codes—William Friedman is known for his distinguished career as an expert codebreaker with the U.S. Army during World Wars I and II. But although Friedman is one of the biggest names in cryptanalysis—he coined the word itself—historians often skip over the fact that his wife, Elizebeth, was every bit as skilled a codebreaker. Her accomplishments have been (sometimes deliberately) kept from the spotlight.

The youngest of nine kids in a Quaker family, Elizebeth Friedman (née Smith) was born in rural Indiana in 1892. (Her mother spelled her name unusually, swapping out the a for another e, reportedly because she disliked the nickname “Eliza.”) Young Elizebeth was bright and displayed a talent for languages, and was determined to go to college despite the discouragement of her father—so determined that she eventually ended up borrowing tuition from him at a 6 percent interest rate. After starting out at Ohio’s Wooster College in 1911, she finished her degree at Hillsdale College in Michigan, majoring in English lit. She also studied German, Greek, and Latin at Hillsdale, and it was there that she discovered her lifelong love for Shakespeare.

After graduation and a brief spell as a substitute principal at an Indiana high school, Elizebeth traveled to Chicago in 1916 and visited the Newberry Library, where Shakespeare’s First Folio was on display. There—having quit her principal job out of boredom—she asked the librarians if they knew of any research or literature jobs available. Within minutes, she was being introduced to the eccentric George Fabyan, who ran a 500-acre private research facility called Riverbank in nearby Geneva, Illinois. At the time, Fabyan also employed a scholar named Elizabeth Wells Gallup, who was trying to prove that Sir Francis Bacon had actually written Shakespeare’s plays. Gallup needed a research assistant. Elizebeth was taken to Riverbank for an interview, and a few days later, she was hired.

At Riverbank, Elizebeth worked on a cipher that Gallup claimed was hidden in Shakespeare’s sonnets and supposedly proved Bacon's authorship. Riverbank also employed the Russian-born William Friedman, a Cornell-educated geneticist, to work on wheat, although he became increasingly drawn to the Shakespeare project. William and Elizebeth fell in love and were married in May 1917, one month after the U.S. entered World War I.

Riverbank was one of the first institutes to focus on cryptology, and in the early days of the war, the War Department relied upon Riverbank almost exclusively. "So little was known in this country of codes and ciphers when the United States entered World War I, that we ourselves had to be the learners, the workers and the teachers all at one and the same time," Elizebeth wrote in her memoir.

But the Friedmans sometimes worked for other governments, too. After a recommendation from the U.S. Department of Justice, Scotland Yard brought them a trunk full of mysterious messages the British suspected were being used to facilitate insurrection in India, which was then a British colony. By cracking the codes, written in blocks of numbers, the Friedmans exposed the Hindu-German Conspiracy—in which Hindu activists in the U.S. were shipping weapons to India with German assistance. The resulting trial was one of the largest and most expensive in U.S. history at that time, and it ended sensationally when a gunman opened fire in the courtroom, killing one of the defendants before being killed by a U.S. Marshal. Unaware of the Friedmans' codebreaking work, he apparently believed the defendant had snitched.

The war ended in 1918, but Elizebeth and William continued their work for the military, and in 1921, they moved to Washington, D.C. to focus on military contract work full-time. Elizebeth loved the change of scenery, going from the rural countryside to the city—she recalled going to the theater several times a week when she first arrived in D.C.

After a period spent working for the Navy, she left the paid workforce for a few years to start raising her children, Barbara and John. But in 1925, the Coast Guard came calling, asking for her help on Prohibition-related cases. Soon she was cracking encrypted radio messages used by international liquor-smugglers who hid booze in shipments of jewelry, perfume, and even pinto beans.

Elizebeth proved to be a pivotal asset to the Coast Guard during Prohibition. She was the star witness in a 1933 trial following the bust of a million-dollar bootleg rum operation in the Gulf of Mexico and the West Coast. When asked in court to prove how “MJFAK ZYWKB QATYT JSL QATS QXYGX OGTB" could be decoded to "anchored in harbor where and when are you sending fuel?"—just one of perhaps thousands of coded messages that formed key evidence in the trial—Elizebeth asked the judge to find her a chalkboard. She proceeded to give the court a lecture on simple cipher charts, mono-alphabetic ciphers, and polysyllabic ciphers, then reviewed how, over the course of two years, she and her team painstakingly intercepted and deciphered the radio broadcasts of four illicit distilleries in New Orleans, explaining what each transmission meant. Special Assistant to the Attorney General Colonel Amos W. Woodcock later wrote that Elizebeth's obvious proficiency "made an unusual impression."

Just a year later, Elizebeth again proved invaluable to the Coast Guard in the "I’m Alone" case, in which a ship flying a Canadian flag was sunk by the Coast Guard after refusing to acknowledge a "heave to and be searched" signal. After Canada filed a lawsuit against the U.S. for $380,000, including damages for the ship, its cargo (which included liquor), and personnel losses, Elizebeth came to the rescue: She was able to solve 23 separate encoded messages from the ship that proved the I’m Alone was actually owned by American bootleggers, despite its Canadian decoy flag. The main charges against the U.S. were dismissed, and the Canadian government was so impressed with Elizebeth’s work that it asked the U.S. for her help in catching a ring of Chinese opium smugglers. Her testimony later led to five convictions.

William and Elizebeth FriedmanWikimedia // Public Domain

Elizebeth and William weren’t just code-breakers by day. Their personal fascination with cryptology permeated their whole lives, in work and in play, and built a unique bond between them. The pair used ciphers in family gatherings with their children, and developed various codes to communicate with one another as well throughout their long relationship. They were even known to host dinner parties where the menus were encoded—in order to proceed to the next course, their guests would have to solve the puzzles.

With the start of WWII, Elizebeth began working for the Coordinator of Information, an intelligence service that served as the forerunner to the Office of Strategic Services (OSS), the predecessor of the CIA. While William won huge acclaim for leading the team that figured out Japan’s Purple Encryption Machine—a discovery that gave the U.S. government access to diplomatic communications prior to the bombing of Pearl Harbor—Elizebeth’s successes were less publicized. In fact, researchers have described hitting a "brick wall" when trying to find more details of her wartime activities. But according to Jason Fagone, author of the recent biography The Woman Who Smashed Codes, Elizebeth spent the war as a Nazi spy hunter for the FBI, breaking German codes and working closely with British intelligence to bust Axis spy rings. J. Edgar Hoover wrote her out of the story once the war had ended, classifying her files as top-secret and taking the credit for himself.

One piece of Elizebeth's work for the FBI is slightly better-known, however: Her code-cracking expertise was key in solving the "Doll Woman Case" of 1944, wherein Velvalee Dickinson, an antique doll dealer based in New York City, was convicted of spying on behalf of the Japanese government. Elizebeth's work helped prove that letters Dickinson had written, though seemingly about the condition of antique dolls, actually described the positions of U.S. ships and other war-related matters and were intended for the hands of Axis officials. As Fagone notes, although newspapers of the day wrote breathlessly about Dickinson as "the War's No. 1 woman spy" and how her codes were cracked by "FBI cryptographers," Elizebeth was never mentioned.

Elizebeth retired in 1946, a year after World War II ended, and William did the same the following year. In 1957, after many years of research, they finally published their masterwork on the bard, The Shakespearean Ciphers Examined, which won awards from several Shakespeare research facilities. In contradiction to Gallup's theories, the Friedmans denied that Francis Bacon had written any works known as Shakespeare’s, and they even buried a cheeky message to that effect on one of the pages—an italicized phrase that when deciphered reads: "I did not write the plays. F. Bacon."

After William’s death in 1969, Elizebeth dedicated large amounts of her time to compiling and documenting her husband’s work in cryptology, rather than celebrating her own extraordinary achievements in the field. The fruits of her effort would eventually become part of the George C. Marshall Research Library, named after the WWII-era Chief of Staff of the U.S. Army.

Elizebeth herself died on Halloween 1980 and was interred with her husband at Arlington National Cemetery. Inscribed on their double gravestone is a quote, not by William Shakespeare, but commonly attributed to Francis Bacon: "KNOWLEDGE IS POWER." It too is a cipher—when decrypted, it reads "WFF," William Friedman's initials.