Introduction: Get Your Own Enigma Machine Replica

Background: During WWII the German military did see the need for secure communication between all it's troops and for that purpose they did take a commercially available enigma and modified it to increase the security in it. Then they used it across all military branches for communications, by the end of the war it was 60 different networks using enigma with numerous machines in each network.
Enigma was thought to be unbreakable but smart people from Poland and UK figured out ways to crack the code mostly due to bad habits by the operators or bad procedures used.

This instructable shows what is involved with assemble your very own enigma. This is a kit from meinenigma.com and it is an electronic enigma replica designed to be as close as economically possible to the original German enigma. The size and functionality is like the original but at a fraction of the cost.

The kit comes with all components and includes a step by step manual with pictures. Read through the provided assembly instructions at least once before even turning on the soldering iron. You can even start reading the manuals now since they are available for download at https://meinenigma.com/downloads/

What you need:

  • a complete kit from meinenigma.com
  • 2 x AA battery (or powered from USB)
  • 1 x CR2032 coin cell battery for the real time clock
  • soldering iron
  • some soldering
  • a cutter
  • small wrench or pliers
  • screwdriver
  • patient

Step 1: Step 1: Verify the Kit

Make some space and lay out all components. Verify what you have against the BOM. The components are all packed in small bags and it's probably best to not take them out until you need them since it might be hard to identify them otherwise.

Step 2: Step 2: Assemble the Lamp and Keyboard

We start with this board because it is more space around components on it and then you get some practice soldering things together. During the assemble you also end up with some parts needed for the main board (cutoff from the LED)
It starts with the small components so you have less in the way when it comes to solder them in, and then moves on to the larger components. The components are in numbered bags and you just find all "L" bags and solder them in, details are in the instructions.

Once it's all soldered on you can take the screwdriver and screw on the standoffs so it comes up from the table a little.

Step 3: Step 3: Main Board

This is the top board with most components on it. Here you do same as you did with the lamp and keyboard, follow the instructions which basically states take bag M02 and solder in the components, then bag M03 and so on.

Once it's all soldered in place and you screwed on the standoffs you can now connect the two boards with the big ribbon cable and try it out.

At this point everything except the physical plugboard should work. You can even start encrypt/decrypt messages since the plugboard can be simulated.

Step 4: Step 4: Plugboard

The plugboard only have 3 types of components but it's many of them. The good news is that the 26 jacks do not need to be soldered on, you just screw them on.

This board is connected with a 4 wire cable. Make sure the cable is same way on both boards.

Step 5: Step 5: Plug Cables

The kit comes with 3m cable. You cut this in 10x30cm pieces. Strip the end of each wire and put it in the plugs and screw it tight. This is now your plug cable to be used on the plugboard.

Step 6: Testing/Using It

Once you assembled all the parts you can now start using it. The first thing to do is to understand how to configure it and the details are in the documentation but basically you

  • turn on the power by turning the knob to the right one step
  • select what model you want to emulate, M3 or M4
  • turn the knob one step more
  • select what rotors to use as key
  • turn knob
  • select reflector
  • turn knob
  • select plugboard setting
  • turn knob
  • start encrypt/decrypt messages.

All settings can also be done over the serial port, connect a computer to the USB port and start a serial terminal. One way to do that is to install the arduino IDE which comes with built in serial terminal, and then you can also change the firmware (source code available at http://github.com/lpaseen/meinenigma )

On internet it exist forums to exchange enigma encrypted messages, one place is

http://enigmaworldcodegroup.freeforums.net/

It is also a lot of information about the procedure that was used to create enigma messages.

Now when you done playing with it you may want to still show of your work, you can then set it to show the time. If you do that you need to run it on external power (USB charger with microUSB connection) and remove the batteries or the batteries will be drained in a few hours.