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  • Writer's pictureMatilda Butler

Your Assignment: Break This Code!

A Challenge for You: Break This Code!

Just imagine. It is WW2, and you have found a way to contribute. As a kid, you were always good at solving puzzles. You and your best friend, Sue Ellen, liked to make up codes and send each other messages, knowing you two alone could figure out the text. One Christmas you and Sue Ellen both asked for and received fancy decoder rings. Such fun.

Later, in college, you studied math even though your other classmates were mainly males. Your parents were proud of you but thought it all a bit foolish. After all, you were female. What in the world could you do with this training.

Then came WW2. You considered dropping out of college — hoping there would be a way you could help America win, especially after Pearl Harbor was attacked. Then a recruiter came to campus to interview all the female math students. You were asked to complete crossword puzzles and asked if you were engaged. You had always loved crossword puzzles, so the test was easy for you. Actually, you finished the test in record time. And, since you weren’t even dating anyone seriously, you could easily respond that you weren’t close to marriage.

Your Invitation

Not long afterward, you received an invitation, a secret invitation, to a meeting where you were offered the opportunity to take a code-breaking course. You responded with a strong “Yes”. You passed the course.

You weren’t exactly sure what to make of it, especially because it was all “hush hush” and you couldn’t even talk with your roommate or your parents about this. However, once you finished your undergraduate degree—actually you finished Magna Cum Laude—you received an invitation to join the Navy as a civilian employee. Although some of the new employees were hired as cryptographers (code makers), your job was as a cryptanalyst — a code breaker.

Your Cover Story

When you parents and others asked what you did, you just gave a modest laugh and said something like, “I sharpen pencils in the office” or “I empty trash cans” or even occasionally “I sit on the laps of officers.” The whole point was to make light of your unimportant work. No one believed anything else. After all, you were just a “woman.”

Every One's Talent Was Needed and Valued

Although most of the WW2 female code breakers were white, there was a unit of Black women who worked at Arlington Hall Station. The names of these women have mostly been lost to history -- only two have been discovered:

  • Annie Briggs, head of the production unit -- that worked to identify and decipher codes; and

  • Ethel Just, head of a team of translators.

During the war, secret meant secret. Each unit worked independently from the others. There was no cross communication. Besides, this was still the time of Jim Crow laws and that would have made the Black code breakers even less likely to have been known. Hopefully, more of their names will be discovered in the future.

Four Code Breakers

Here are the names of four white “Code Girls.”

  • Agnes Meyer Driscoll – broke the Japanese M-1 cipher machine

  • Virginia Dare Aderholdt – decrypted the Japanese surrender message

  • Margaret Crosby – worked as a cryptographer for the OSS' Greek Desk

  • Genevieve Grotjan Feinstein – found the crucial break in the Japanese Purple cipher

Genevieve Grotjan Feinstein

I want to focus on Genevieve Grotjan (Feinstein). Here is an except from Frank B. Rowlett: A Personal Profile by Theodore Hannah.

“Finally, Genevieve Grotjan finds the evidence we are looking for. Time is about 2 p.m. Ferner, Small, and I are at table in working area discussing prospects and reviewing work. Grotjan enters room, obviously excited, politely interrupts, asks if she can show us what she has found.

“She takes us to her desk in next room, lays out worksheets, points to one example, then another, then a third. She stands back, with eyes tranced behind her rimless glasses.

“Al Small dashes around the room, hands clasped above his head like a victorious prizefighter. ‘Whoopee!’ he yells.

“Ferner, the quiet one, clasps his hands, shouting ‘Hooray, Hooray.’

“I jump up and down – ‘That’s it! That’s it!’

“The room gets crowded; everyone in section suddenly in room. Friedman comes in and asks, “What’s all the noise about?”

“I settle down and say, ‘Look what Miss Grotjan has just discovered.’ Gene(vieve) wipes her eyes, tries to regain her composure. I point to the worksheets – ‘Gene’s found what we’ve been looking for. Look here, and here, and here.’

“Friedman examines each one and understands what he sees; he looks suddenly tired. We take a break and send out for Cokes. The excitement gradually wears off and we look ahead to the next step.” – Frank Rowlett

“That next step would soon lead to the solution of Japan’s highest level diplomatic cipher system, the so-called Type “B” machine, better known as “Purple.” What young, studious Genevieve Grotjan had discovered on that warm Friday afternoon in September 1940 represented the decisive breakthrough into a highly sophisticated machine system that for 18 months had stubbornly resisted the concerted attack by some of the best cryptanalysts in the world. Its solution has been called “the greatest feat of cryptanalysis the world had yet known,” one which, in the words of another author, “involved a unique intellectual effort of heroic proportions.”

Let's Offer Our Thanks to Genevieve and All the Other "Code Girls"

We should all offer our thanks to Genevieve Grotjan for breaking the Purple Code. Because of her efforts, America learned of Japanese shipping routes and troop movements.

While acknowledging the almost 11,000 women who helped create and break codes during WW2, we thought you might enjoy becoming a cryptanalyst — a code breaker.

Now, Back to You and Your Code-breaking Assignment

Here’s your coded message. It is a substitution code and nothing at all like the complex codes of WW2. But it is still fun.

Below is the key to decoding the message. Decode it by substituting the coded letter in the top row that corresponds to the letter in the bottom row. (This code is provided by the USPS to go along with their new stamp honoring the Women Cryptologists of World War II. Their stamp inspired this blog. And the more immediate inspiration came from a dear friend, Kris Maas, who sent me a sheet of the stamps.)

I've included a sample coded message and the decoded message.





What is the decoded message? Have fun.


Post-Script: Thanks to long time family friends, Alan and Jackie Mayers, we visited the National Security Agency’s cryptologic museum in Maryland a few years ago. The range of codes was fascinating and not only included many early coding schemes as well as WW1 and WW2 codes. I found their display of hobo codes fascinating. I remember my father telling me about hobos during the depression who came into the office where he worked. Each one always walked over to the same desk where a man gave a few coins, even though it was the first time the hobo had been inside. No one could figure out the code, but knew there was something marked on the desk.


No Code Needed...We Invite You...

Check out our POWER PINS. This set of three pins is a great reminder of our own empowerment as well as a way to honor all the hardworking women who have paved the way for us.

We can make our own contribution to the women of the next generation.

Wear these yourself or turn them into a gift for a family member of a BFF.

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Sep 30, 2022

Great story about Genevieve Grotjan. Have the details of that great intellectual effort ever been spelled out?


Sep 29, 2022

Loved this story and the cryptogram was fun...especially since I can solve it without looking at the key. And I enjoy that particular fruit every day. Doc's orders. Thanks

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