Welcome to an insight into the behind-the-scenes work of your favorite cryptologists. We started the rainy morning by grabbing coffee (I know that may come as a shock) on the way to our morning class. We had two whole class periods in one day dedicated to the inner workings of the Bombe machine that Turing used as a weapon against the Enigma. Makayla for one is glad that this class is out of the way because it was very nerve-wracking to hear Dr. Woodard and Dr. Millichap say that they needed to talk about and finish the bomb before the flight while we were walking through Atlanta airport. We were worried for a minute that we would not even be let on the plane. Luckily, we made it, and no explosions have occurred... yet. Our brains may explode just a little bit from the amount of information we have taken today, though.
In the first class, we discussed how the Bombe machine worked. The Bombe machine helped WWII cryptologists determine the daily settings of the German Enigma machine used to encrypt important communications. Unlike the Imitation Game movie, the process of getting the correct daily settings was not a one-person job. Also, Turing and his colleagues were using cribs to set the Bombe machines from the beginning (we added this for you Dr. Woodard). There was sadly no mad dash back to Bletchley at 2 am to finally try setting the machine according to a crib- Hollywood may be entertaining but sadly it is not always accurate. Today, we got to pretend that we worked in Hut 11 at Bletchley as WRNS tasked with finding the “story” with only a menu we got from another hut. The “story” is what the WRNS called the rotor settings followed by the central letter (example: NBI:S). The menus contained settings for the drums on the front of the machine (they look like dials in the picture below) and how to wire the back of the machine. The central letter is the letter where the charge is inputted on the Bombe machine. The crazy thing was that the WRNS did this every single day without knowing what they were doing and why they were doing it. They simply followed the menu they were handed and then passed along their results all day with huge, loud machines
The Bombe Machine
After the machine had been set up, the WRNS would run it and the drums would turn and turn. Eventually, they would stop (usually). The stop would reveal a “story.” However, not every stop was the correct “story.” So, the next step was to put the “story” through the checking machine to see if it was correct. The checking machine was used to see if the story could work or if it was a false stop by checking for inconsistencies. For example, if A was Plugged to P and then later P was plugged to T, there was an inconsistency, and the “story” was wrong.
Dr. Woodard setting up the Bombe Machine
Next, we pretended that we got promoted (still waiting on the pay raise) and worked with a crib and cipher text to create a menu for Hut 11. We made a “graph” to represent the menu diagram based on the permutations we determined from the cipher and plain text. We aligned the cipher text crib with the plain text and noted the positions of the pairs of one cipher text letter and one plain text letter. If our plain text was “cryptology”, c was position 1, r was position 2, and so on. We represented each letter as a point on our graph and then drew lines to represent a letter encrypted or decrypted into a different letter. This line (edge in graph theory terminology) was labeled with the position the encryption or decryption occurred in. Next, we wrote the menu as one big cycle by finding a path through the diagram by following the edges and ensuring we hit all the letter vertices. Once we had a path, we wrote the edge numbers for the connections between and above our letters. This revealed the drum settings that should be put on the menu. Reading the numbers across gave us the number letter in the alphabet that the drums should be set to. For instance, if 5 was the first edge, the first set of three drums would be set to ZZE. Then, we determined where cables needed to be plugged on the back by determining where the letters occurred in our cycle. For instance, if R was the second letter, the cable went in where there was a bridge between “1 out” and “2 in.” We also chose P to be our central letter and hypothesized that I was plugged to P. So, we put a cable from P to the charge and flipped the I switch on the side of the Bombe machine. Then we turned on the machine and watched it turn until it stopped. We tested this stop using a checking machine and it worked!
After this, we took a much-needed lunch break. Makayla and Ava K. got to meet up with one of their friends from home who is currently studying finance in Leeds! She was in London for the weekend, and they were so excited to squeeze in a short visit. It was so fun to introduce her to everyone and get a little bit of time to share experiences and trade hilarious quotes and embarrassing tourist mistakes.
Due to the rainy weather a bunch of cryptologists ate their lunch in the common room together
In the afternoon, we spent some time learning about how the electrical circuits in the Bombe machine work. To simplify, we explored an example with a 6-letter alphabet and 15 different permutations of letters. We then used the permutations to determine how electricity flowed through the circuit of connected letters. This showed which wires were lit and which ones were not based on an initial charge at A. The machine would do this in mere seconds, let’s just say we were not as speedy as the machine. We were surprised to learn that the inner workings of the Bombe machine are not often taught. Dr. Woodard really nailed it with this lesson, and we enjoyed the challenge! We were also given a challenge exercise of deciphering an Enigma message with a brief crib, which several people immediately were absorbed into. The chance to win a Woodard hat signed by the wizard himself is simply too great a prize to pass up. We heard inside news that some students were going to pull an all nighter to win that hat.
In other news, we got the results of the photo contest for the first week in London. The categories were “Best Scenic Photo,” “Best Group Photo,” and “Most Entertaining Photo.” There were lots of oohs and ahhs for the scenic photos, and lots of laughs for the entertaining photos. For next week, we will be adding a new category called “Zaniest Professor Picture,” so stay tuned for some more laughs next week! Below are the winners of this week’s competition. Congrats to the students who captured these works of art!
Best scenic photo winner by Caitlyn
Most entertaining photo winner by Ella
Best group photo winner by Rhodes
When class finished, we headed back to our dorms to get a much-needed nap before a fun evening. We met up for a delicious group dinner before going to Shakespeare’s Globe Theater to watch “Romeo and Juliet” but make it western. Think Romeo and Juliet with cowboy hats, guns, and salon. The theater is a replica of what it would have been in the olden times so there was no roof- which is not good for a rainy day like today. A lot of crazy moments happened during the show such as Mercutio kissed an audience member- our jaws were on the floor. The show was very funny and entertaining for the first half before things took a trajectory turn. You all should know how the story ends so we will not bother filling you in.
Shoutout to Ava H., Makayla, Josh, Ava K., Anya, Joseph, Nick, Caitlyn and Lorelei for braving the rain to see the end of the show. If you were wondering, there was in fact a group dance number after everyone died.
“What do you do if you get an inconsistency?” “You cry.” -Josh
“I’m not going to bend over because someone might take a picture.”- Dr. Woodard (In the afternoon)
“I might not be a window, but I’m always a pain.” -Dr. Woodard
“Somehow the weird western theme is working.” -Dr. Woodard
"If they get arrested, I am not bailing them out of jail." - Caitlyn
We all made it back to our dorms and are ready to sleep to get ready for the National Museum of Computing tomorrow.
Ava Hershberg and Makayla Carnahan
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