Tag Archives: Anne Frank

A Paradox Wrapped in an Enigma (Machine)

Being a teacher by day, I go through quite a few books. This week, my students and I are wrapping up The Diary of a Young Girl by Anne Frank. Since it’s the only major piece of nonfiction that we read during the year, I love to ground it for my middle schoolers. Yeah, they’re learning about World War II in history right now, but I like to make that connection that this isn’t just a story. This is real.

One of our most recent adventures: the German enigma machine.

Okay, so it was one of those moments that went better in practice at home and in my mind than it did in the classroom, but that doesn’t make it any less cool.

While the workings of this coding typewriter are complex, the concept behind how it works isn’t (once you have the hang of it) and can be done with just four strips of paper.

Enigma Machine

The basic idea: three rotors are set in specific positions and kept there. (Those are the three white strips with the letters and lines on them in the picture.) You then start on the far right side of the “machine” with the letter you want to encode/decode. As you pass through the rotors, the letter changes. Once you hit the far left side, you start backwards. By the time you reach the right side again, the letter is encoded/decoded.

“It takes a long time to do one letter,” my students complained.

“Which is why they used a typewriter to do the work,” I responded.

But you don’t have to have the typewriter to do the work. In fact, even though it does take some time, it’s quite fun to play with and leave secret messages!

Interested in checking out this paper enigma machine? Click here!

And if you do decide to make one (which, by the way, only requires one piece of computer paper), here’s a message for you: