Enigma machine workshop

Enigma machine - top secret messages

The Enigma machine was devised by a device used by the Germans during World War 2 to encrypt communications to prevent it falling in to the hands of the British and their allies. It was a very intricate device and the scrambled messages it created should have been un-crackable. In fact, the Germans thought they were but the British, headed by Alan Turing, had cracked Enigma and were able to read German communications almost at will towards the end of the war.

Looks simple but it was thought to be uncrackable

The machine was produced in a number of different variants to suit the requirements of different factions of the German armed forces and government. To the un-trained eye it looked like a typewriter, but it deviated by having a lamp board (containing a lamp for each letter of the alphabet) above the keys. The operator took the plain message to be transmitted and typed the message in, as each key was pressed and encrypted letter was produced and the relevant lamp lit.

The machine contained a number of rotors that would be varied each day so that the allies would not be able to read that day’s messages even if they’d cracked the previous days messages (not that the Germans were expecting it to be cracked). Every time the operator pressed a key the right-most rotor rotated one place. This meant that cypher used to encrypt the message changed after every letter making it even harder to crack the code. Once the right-most rotor had rotated twenty six times, it would rotate again for the twenty-seventh letter but the next rotor in would rotate one place too. Enigma machines contained three or four rotors and this process continued during the encryption process.

Due to the number of different rotors that could be used, together and a plug-board that provided and extra level of encryption, Enigma machines had up to 159 million million million possible different settings to encrypt the messages. For this reason the Germans believed that Enigma could not be cracked.

The work of Bletchley Park

The first Enigma messages were broken at Bletchley Park in early 1940 and their hand-picked staff continued to break the code throughout the test of the war. It is claimed that the work of the team at Bletchley Park shortened the war by about two years.

Build your own Enigma machine

You can build your own modern-day Enigma machine using a kit that replaces the rotors with electronic circuits. It isn’t cheap, but it does look just like the real thing.

You can also have a go at using a virtual Enigma machine using the Enigma Emulator. This works, but it’s not an Enigma machine.

Alternatively, attend our Enigma machine workshop and build one for yourself using just a Pringles tin; you’ll be able to start encrypting your messages to protect them from prying eyes within minutes.

Don’t forget to visit our Code & Cypher School workshop to find out other methods of encrypting your valuable information.