All Things Enigma Hack Chat

Join us Wednesday at noon Pacific time for the All Things Enigma Hack Chat!

This week’s Hack Chat is a bit of a departure for us because our host, Simon Jansen, has tackled so many interesting projects that it’s hard to settle on one topic. Simon is a multidisciplinary hacker whose interests run the gamut from building an ammo-can Apple ][ to a literal steampunk Rickroller. How about a Bender Brewer? Or a MAME in a TARDIS? Or perhaps making an old phone play music to restore a car by? Oh, and remember that awesome ASCII animation of Star Wars: Episode IV? That was Simon.

So, a little hard to choose a topic, but we asked Simon to talk a bit about his recent Enigma watches. He has managed to put an electronic emulation of the Enigma cypher machine from World War II into both a wristwatch and, more recently, a pocket watch. They’re both gorgeous builds that required a raft of skills to complete. We’ll start there and see where the conversation takes us!

Please join us for this Hack Chat, where we’ll discuss:

  • Where the fascination with Enigma came from;
  • Tools, techniques, and shop setup;
  • Melding multiple, disparate skill sets; and
  • What sorts of new projects might we see soon?

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the All Things Enigma Hack Chat and we’ll put that in the queue for the Hack Chat discussion.

join-hack-chatOur Hack Chats are live community events on the Hack Chat group messaging. This week we’ll be sitting down on Wednesday, February 27, at noon, Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

An Arduino Wrapped In An OLED Wrapped Inside An Enigma Pocket Watch

A pocket watch, tucked into a waistcoat pocket and trailing a long chain, is a retro-hip accessory. A pocket watch gutted of its mechanical innards and updated as a smart appliance might be a horological abomination, but would still be a cool hack. A pocket watch converted to a digital Enigma machine is in a class all by itself.

[Simon] admits that he has a thing for pocket timepieces, having a sizable collection of old and not-so-old watches, some that even serve for everyday carry. Trouble is, they eventually break, and qualified watchmakers are getting hard to come by. So refitting defunct watches has become a hobby for him, and this example is a doozy. It uses an Enigma emulator running on an Arduino, similar to one that he stuffed into a somewhat oversized wristwatch a few years ago. Fitting it into a pocket watch case required a bit of finagling, including a 0.5-mm thick main PCB that flexes a bit to fit the contours of the case. A small OLED screen peeks through the front bezel, which is done up in an attractive black crinkle finish with brass buttons for a nice retro look. There’s even an acid-etched brass badge on the front cover with his special logo, complete with a profile of the original Enigma rotors.

Very impressive workmanship, and we don’t even care that it doesn’t tell time. Need a little background on the original Enigma? [Steve Dufresne] did a great job going through the basics a while back.

Continue reading “An Arduino Wrapped In An OLED Wrapped Inside An Enigma Pocket Watch”

The Enigma Enigma: How The Enigma Machine Worked

To many, the Enigma machine is an enigma. But it’s really quite simple. The following is a step-by-step explanation of how it works, from the basics to the full machine.

Possibly the greatest dedicated cipher machine in human history the Enigma machine is a typewriter-sized machine, with keyboard included, that the Germans used to encrypt and decrypt messages during World War II. It’s also one of the machines that the Polish Cipher Bureau and those at Britain’s Bletchley Park figured out how to decipher, or break. Most recently the story of how it was broken was the topic of the movie The Imitation Game.

Let’s start with the basics.

Continue reading “The Enigma Enigma: How The Enigma Machine Worked”

Decoding Enigma Using A Neural Network

[Sam Greydanus] created a neural network that can encode and decode messages just as Enigma did. For those who don’t know, the Enigma machine was most famously used by the Germans during World War II to encrypt and decrypt messages. Give the neural network some encrypted text, called the ciphertext, along with the three-letter key that was used to encrypt the text, and the network predicts what the original text, or plaintext, was with around 96-97% accuracy.

The type of neural network he used was a Long Short Term Memory (LSTM ) network, a type of Recurrent Neural Network (RNN) that we talked about in our article covering many of the different types of neural networks developed over the years. RNNs are Turing-complete, meaning they can approximate any function. [Sam] noticed the irony in this, namely that Alan Turing both came up with the concept of Turing-completeness as well as played a big part in breaking the Enigma used in World War II.

How did [Sam] do it?

Continue reading “Decoding Enigma Using A Neural Network”

VCF East: Enigma Machines In The Flesh

At the end of World War II, the Germans ordered all Enigma cipher machines destroyed. Around the same time, Churchill ordered all Enigma cipher machines destroyed. Add a few decades, neglect the efforts of Polish codebreakers, and make a movie about Alan Turing and an offensively historically incorrect love interest, and you have a mystique around these rare, innovative cipher machine.

At the Vintage Computer Festival East, I was privy to what is probably the largest collection of Enigma machines on the planet. The exhibit comes from [Tom] and [Dan Perera] of Enigma Museum. Right now, they’re they only place where you can go out and simply buy a real, wartime Enigma machine. The price? Well, there is a pair of million-dollar Apple I boards at VCF. The Enigmas go for about a fifth of an Apple I.

Continue reading “VCF East: Enigma Machines In The Flesh”

3D Print An Enigma Machine That’s Close To The Real Thing

The Enigma machine as used by the German military during World War Two exerts a curious fascination among our community of hardware hackers and makers. Perhaps it is the mechanical complexity of the machine itself, or maybe the tale of how its encoded messages were decrypted by Allied codebreakers that contributes to this interest, but whatever it is we’ve seen a succession of Enigma-related projects over the years that shows no sign of abating.

The latest Enigma project to come our way is a particularly nice one from a group of first year students at CentraleSupélec Rennes, in Northwestern France. Their Réplique Enigma is a fully mechanical Enigma replica using 3D printing techniques, and unlike so many replicas which use modern electronics it has a set of rotors just like those you would have found in the original. The rotors themselves have a 3D-printed plastic shell which houses brass contacts and the associated writing, while the keyboard and lamp board are both made from plywood. Rather than trying to replicate the original switches from the keyboard they are using modern microswitches, however the keys themselves are upright posts that resemble the original. An AZERTY layout may not have been present on the real Enigma machines, but lends a pleasing twist to the build.

It’s worth browsing all the pages for this build, as the front page does not necessarily capture the whole build. The rotors set this Enigma apart from many of the replicas we’ve featured in the past, so you may find it interesting to take a look and make a few comparisons.

Paper Enigma Machine

It was high-tech encryption for an important period of time in the mid-1940s, so perhaps you can forgive us our obsession with the Enigma machine. But did you know that you can make your very own Enigma just using some cut out paper strips and a tube to wrap them around? Yeah, you probably did. But this one is historically accurate and looks good too!

If you just want to understand how the machine worked, having a bunch of paper rolls in your hands is a very intuitive approach. Alan Turing explained the way it worked with paper models too, so there’s no shame there. With this model, you can either make the simple version with fixed rotor codes, or cut out some extra slip rings and go all out.

What is it with Hackaday and the Enigma machine? Just last month, we covered two separate Enigma builds: one with a beautiful set of buttons and patch cables, and another in convenient wrist-watch format. In fact, one of our first posts was on a paper Enigma machine, but the links are sadly lost to bitrot. We figure it’s cool to repeat ourselves once every eleven years. (And this one’s in color!)