I know nada about radio and comms, but that seems pretty awesome.

Here's an Enigma emulator made from a Pringles can and a printout listed in text for the video. It works the same as a real 3-rotor Enigma machine, including the plugboard scrambler.
It's tricky to use, but it's as secure as the real deal.


There are also several software emulators.
Here's one: https://www.101computing.net/enigma-machine-emulator/

Enigmas are fascinating devices. Once you dig into them, you'll find that they are devilishly simple.
There's plenty of info about them online and there's also a detailed book available: LINK

Very popular topic. There are apps for Android and iOS. Dozens of books on Amazon. Microcontroller based versions you can build from kits.

Haven't seen a kit that is a true, mechanical representation, though.

What always confused me was the process if creating an encoded message (any of the nations methods) first you have to write it THEN you have to encrypt it on paper then you send the ciphertext.  So it would have generated(and required) a substantial amount of paper to send and receive messages. Where did that scratch paper go?

In the old days it went into a burn barrel, later on a microfine shredder. A vulnerability, to be sure, much like USB memory sticks are today.

That MI6 was able to decipher Enigma code was not the fault of the machine, but the way it was used.

Tradition says you have to eat it.

Each day the primary key changed in each major command structure. The Germans, using the day key, would transmit the unique message key twice. Then, the operator would switch to the message key and encode the message. Lots of vulnerability there. Additionally, the plug board added lots of possible permutation, but could be mathematically zeroed out. Good times. TT

Couldnt a 1 time pad be used to transmit the key and avoid decoding if the daily key couldn’t be shared in person?

Then once the key is decrypted the message could be decrypted.

Isn’t it similar to EAMs? Code has to match in order to access orders?

The Enigma machine was originally used starting in the early 1920s to make commercial and financial transactions secure.

Look carefully at the keyboard and lamp panel. Notice anything odd?

Click To View Spoiler

Fell down the internet rabbit hole reading about the Enigma after this thread was started.
Had the Germans been diligent with their operational instructions on switching wheels and encoding their messages to preclude standardized formats it is not likely the Enigma code would have been broken.

Sloppy cryptography practices are what let the camel's nose under the tent, per se, which gave the allies enough information to begin deciphering the code.

A long time ago (1987, I think) I wrote an Enigma program.

The Unix system at the time had a program called "crypt" which was an implementation with a single rotor.
To make it easy to use, it generated mappings for all the ASCII characters in its "wheel", and included the reverse mapping in the same wheel.
So you could encrypt something with a password, then take the encrypted data and feed it back into the same program, with the same password, to recover the original text.

I became interested in it when one of the salesmen at our company (probably the best salesman) had a falling out with the owners.
After he left one of the owners came to me and asked what I knew about crypt. Seems that he had encrypted all of his sales lead data and was refusing to give them the password.
Talking to him later, I found out that the falling out was over a big sale he landed, and he didn't get the (sizable) commission on it, they told him there was a cap (never mentioned before).
He was willing to give them the password if they had paid his commission.

Anyway... I did some digging, and found out that it was possible to break the encryption if you had enough data.
Since it was encoding ASCII, there were only 256 characters, and the rotor did a complete "revolution" with 256 characters input, then repeated the same mapping.
So if you took blocks of 256 characters, with enough of them and assuming the character distribution for the language, you could relatively easily work out the mapping.

George didn't leave enough big files to make that viable, so I never managed to break his encryption.

But it made me interested in writing my own.
What I ended up with was three rotors, but I didn't do reverse mappings.
The mappings were defined by a random number generator using a seed derived from the password.
When encrypting, rather than moving the first wheel on notch, and doing an odometer type of progression, I rotated each rotor randomly selected a random number of notches (0 1 or 2), derived from the random number generator.

To decrypt it used an option (or later, just a different name -- link) to generate reverse mappings for the rotors.

If anyone is interested in the source, let me know and I will dig out a copy.

So without the random rotor increment, it would have not repeated its mapping for 256*256*256 = 16,777,216 characters, and a darn sight more once you throw in the randomization.

On the subject of code and coding during WWII, I highly recommend the book, "Between Silk and Cyanide." It is a very good read...

Just finishing that book now, and concur.

The enigma is good, but not unbreakable. The one time pad is a better solution as detailed in the book, and is still used today with shortwave numbers stations. There is information here:
http://users.telenet.be/d.rijmenants/en/onetimepad.htm
Note he shows how to make a key for any message, and you can find recordings of numbers broadcasts here. search for "E11" for an english language station.
https://www.numbers-stations.com/database/?q=search/node/e11

Personally I like the CT37 checkerboard, but it needs an @ sign for email addresses, possibly replace the , (92) to modernize it. Another option might be to use the = as a substitute as an email address would be obvious in context.
Attached File



Python has a "secrets" module that has a cryptically secure random number generator which I have used to generate a pdf of a one time pad. This is all for fun though as you would have to take a computer permanently offline to keep the pad secure.