Those who follow this blog via the RadioHistory tag know I like to read and write about various aspects of how radio influenced events in the past, particularly in terms of covert activity. I’m currently putting together a posting that will make more sense if the reader is aware of Germany’s World War II Enigma machine.

Everyone’s heard of Enigma, but how did it work and how did the operators at each end of the encryption process set it up?

You can read through tedious explanations online but they don’t really give you a feel for Enigma’s operation. Thanks to modern technology, you can operate an Enigma-equivalent on your smart phone, computer or as a kit.

Of the three mentioned below, keep in mind that they are not simply random encryption/decryption gimmicks – these simulators emulate the correct parameters of the real Enigma in terms of how the “key” is set up. These keys changed on a daily basis and consisted of five variables. Together, they provided 1.07 x 10^23 possible combinations of encryption.

The five variables making up the daily key were:

• Which rotors were used (3 or 4 of up to 8)
• Rotor order placement
• Rotor initial settings
• Reflector in use (each having a different pin-out)
• Jumper configuration (up to 13 were typically used)

In addition to having differing pin-outs themselves, the rotors were notched and cammed so as to toggle (with each press of a key) the other rotor(s) in such a way as to add complexity to their movement so that they didn’t simply emulate an odometer in their movements relative to each other.

Since the three Enigma simulators below mimic the real Enigma, they are not only compatible with each other, but with genuine messages from World War II as long as that day’s key is made known.

For Droid phones, check out Enigma Simulator. It’s a freebie.

For PC’s, there’s the Enigma Simulator (what else c/would they call it!), also free. This website contains a wealth of info on Enigma’s history, operation, photos and even sources of where you can buy an original Enigma (better have deep pockets). There’s also a challenge where you can try your hand at decrypting intercepted messages.

If you like to solder and a real Enigma is too rich for your blood, there’s the Enigma-E kit, wooden box sold separately. A browse around their website is also worthwhile.

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Using the PC program with initial rotor settings of 05-18-16 (or the Droid app with rotor settings of E-R-P):

NCVRH CUNYO MUJPX JSTWP

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One Response to “Understanding Enigma with apps, software or a kit”

1. I Spy says:

   October 2, 2012 at 10:59 am

   Rotor: 17-18-16 (Q-R-P):

   RYABY WNSRA

   Reply