The Woman Who Smashed Codes

by Jason Fagone

Throughout 1940 and the first half of 1941, the coast guard was pumping solved puzzles to the FBI on a steady basis, dozens per week, hundreds of messages on each clandestine network and ultimately thousands taken all together. Yet this relationship between the coast guard and the FBI only went in one direction. SIS agents in South America never sent useful information or evidence to the coast guard codebreakers. Worse, the FBI systematically obscured all traces of the coast guard’s deep involvement in the spy hunt. When Elizebeth sent them a decrypt, the FBI placed it in their own SIS filing system, with a new four-digit identifying number, and the FBI invented new names for the radio networks that Elizebeth had already named. This is how the history of the Invisible War would become distorted; these are the small decisions that erased Elizebeth from the record and later allowed J. Edgar Hoover to take credit for her achievements. “A considerable amount of the investigation conducted relative to these espionage groups was based on information obtained from the messages transmitted to and received by the clandestine stations,” the FBI wrote after the war in a three-volume history of the SIS. “The technical facilities of the Bureau were used to monitor the several German transmitters, and by analysis and coordination of information obtained from the decodes of the messages, furnished by the Technical Laboratory, and the intensive investigation by SIS representatives, the pe...