[2] She was later assigned to the Venona project, trying to decode encrypted messages sent by the Soviet KGB and Main Intelligence Directorate (GRU).

[4] She made a significant breakthrough in November 1944, which allowed American cryptographers to recognize when an individual one time pad cipher was (improperly) reused.

[6] After resigning from government cryptanalysis, she joined the faculty of George Mason University, where she briefly served as a professor of mathematics.

[4][2] In 1943, Genevieve Grotjan married the Manhattan Project chemist Hyman Feinstein, who worked at the National Bureau of Standards.

[6] Genevieve Feinstein Award in Cryptography (George Mason University)[2] Her breakthrough in deciphering the Purple machine has been called, in the Encyclopedia of American Women at War, "one of the greatest achievements in the history of U.S.