I am reading the book Code Girls, the true story about the thousands of women who worked decoding WWII message traffic for the Army and Navy. It is a fascinating look at how they shaped the crypto and spying industries, and largely an unknown and untold story. I would recommend it highly for your own reading.

One of the women featured in this book is Elizebeth Friedman. She was one-half of a power couple that worked on code breaking and is documented in another book called The Woman Who Smashed Codes that came out last year. Her role is mentioned in Code Girls, but the focus is more on others who are even less famous. The couple met at the offices of an eccentric philanthropist named George Fabyan, who thought that Bacon wrote Shakespeare’s works and wanted some crackerjack researchers to prove it. The couple ended up falling in love with each other and disproving the Bacon theories once and for all.

There has been a lot written about the activities of the British coding group at Bletchley Park (and you can read some links to them here), but not as much about the parallel American efforts to decode the German Enigma and Japanese Purple codes that were used during the war. What is interesting about this book is how it talks about the lives of ordinary women who were plucked from being school teachers, clerks, and recent college graduates into this top-secret life in the nation’s capital and elsewhere to help the war effort.

Why were women chosen for this task? Several reasons. First, most of the men were off fighting the war, so the potential employment pool was diminished. Second, the military found that women made for better code breakers: they had better concentration and more of an eye for detail. Many of them were math and science majors and liked the kind of work that was involved – this was an era before we started telling girls that they weren’t good at math! Finally, the country needed thousands of them for this job. In some cases, entire graduating classes were hired on the spot. All of the women had no idea what they were signing up for, and often left their lives with nothing more than a few dollars in the pocket and a one-way train ticket to DC.

The Army and Navy had different recruiting strategies and set up competing organizations, based in different parts of DC. Early on, one group worked on messages that were received on odd-numbered days and one on even days. That wasn’t very productive, and eventually the two sorted out different theaters of war to focus on.

Two myths are busted in this book. The first is that people who were good at solving crossword puzzles made for good code breakers. That isn’t necessarily accurate, because crosswords are built with escalating clue difficulties, since most people start at the upper left and work their way down the puzzle. Code breaking is very tedious, and you have to deal with tons more frustration as you run into big roadblocks in figuring out patterns as the codes frequently change.

Second is that decoding intercepts could have helped prevent Pearl Harbor. That might have been the case had the US tuned up its efforts but that wasn’t possible during peacetime, given the climate that we had before we entered the war. Decoding intercepts was one of the reasons why we were able to dominate the Pacific theater and sink so many Japanese ships. Often, our military was reading their messages concurrently with their intended recipients, and had to stage a fake aircraft fly-over to hide the real source of their intelligence on the Japanese Navy’s movements.

An interesting side note: this past week my colleague Elonka Dunin (who has spent time with the Cryptos sculpture at the CIA headquarters building) published a paper about the Friedman tombstone and how it contains a hidden cipher. Can’t see it? Look closer. That is why most of us would be terrible code breakers.