Genevieve the cryptanalysis genius
While reading Martin Gardner’s Codes, Ciphers and Secret Writing book, page 8, line 6 of the first paragraph, Gardner briefly talked about Japan’s PURPLE machine code. So what I did was, I also briefly researched it and its history and came across this female genius ‘Genevieve Grotjan’.
Throughout history, females have been widely known for their code-breaking capabilities to the extent where thousands of them were left out of history books. Some that we a know little about and some that we don't even know existed or still do exist. In this Article, I’ll talk about one of many female cryptanalysis geniuses and her journey through breaking PURPLE cipher as well as her work during the Cold war Venona project.
Born in Buffalo, New York of 1913, Genevieve had a passion for Mathematics since young age and aspired to become a mathematics teacher by attending the University of Buffalo. Not being able to secure her dream job in education, Genevieve joined the Railroad Retirement Board which eventually led her to join the Signals Intelligence Service (SIS), the United States Army codebreaking division through World War II, due to her excellent score in a civil service mathematics test which caught the attention of William Friedman, the head of the research division of SIS. This followed working for 18 months along with fellow junior cryptanalysts on Japan’s PURPLE machine cipher to decipher the encrypted messages exchanged between the Japanese Empire and its embassies in foreign countries for diplomatic and intelligence information gain. The pressure on the Army’s Signals Intelligence Service division was immense, Genevieve however, did not crack under the vast amount of stress piled on top of her shoulders and would spend hours analyzing and carefully studying the sheets of codes sent by the PURPLE machine.
By September 20, 1940, Genevieve made the ground breaking discovery of identifying a certain repetitive behavior in the code which eventually lead to the exploitation of the system. Team chief, Frank Rowlett, was so elated by her discovery that he bought a round of Cokes for the entire team .This eventually lead to the creation of an equivalent machine by the SIS which was able to intercept almost all messages sent and received by the Japanese government and its embassies around the globe. During World War II, the successful manipulation of the PURPLE machine produced critical intelligence in the Atlantic and Pacific theaters. This young, brilliant 27-year-old mathematician, who had only recently joined the Signal Intelligence Service, had just accomplished what Friedman had predicted would happen that day would “go down as a milestone in cryptologic history.”
Later on in her life Genevieve was assigned to the Venona Project, which was intended to decrypt messages transmitted by the intelligence agencies of the Soviet Union, the KGB and GRU as an example. This genius made another significant breakthrough in November of 1944 when she discovered an individual One-Time Pad cipher was re-used by mistake. This resulted in the decryption of the Soviet’s intelligence agencies messages. Both of her great discoveries in The Purple Machine and the Venona Project offered American policymakers and senior officials crucial information that would help them during WW2 and the Cold War.
After the conclusion of the second world war in 1945, Ms. Grotjan continued working for SIS as a cryptanalyst and research analyst. She was then awarded the Exceptional Civilian Service Award for her wartime service the following year, and finally in 1947, as the Cold War began, Genevieve resigned and went off to George Mason University to become a mathematics professor and a highly respected and memorable female in our history.
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Authors note: Hope you enjoyed my smol article. I’m open to constructive criticism + please do correct me if any of the information I provided was inaccurate :-)