Image reproduced by kind permission, Director GCHQ

Virtual Typex

A virtual simulation of the British Typex cipher machine

Find Out More Run Virtual Typex

What is a Typex cipher machine?

If you've ever asked the question, "If the Germans had Enigma, what did the British use to encrypt messages?" then Typex is probably the answer you're looking for.

Typex were rotor based, cipher machines which were developed in the U.K. from 1934 onwards. It was based on the commercial German Enigma machine but with a few changes which were made to increase its security.

They were used to send and receive messages for the British during WW2, but also due to its compatibility with Enigma, at Bletchley Park to decipher Enigma messages once the day key had been retrieved using the Bombes.

What was Typex How did it work How do I use the simulation!
Image reproduced by kind permission, Director GCHQ
What does it do?
Image reproduced by kind permission, Director GCHQ
Credits and Links


A number of people I need to say thanks and tip my hat to... .. The National Museum of Computing where my obsession was sparked! Special thanks to John Harper and members of the Turing/Welchman Bombe Rebuild Project who were invaluable sources of information. Make sure you find time to see their rebuilt and fully working Bombe at the museum. .. loads of incredible Typex drawings and information in their archives and assistance finding audio and interviews with Typex Veterans from their Oral History project.

Science Museum Library and Archives .. and especially Dr Elizabeth Bruton, Curator of technology and engineering, who could not have been more helpful getting access to Typex information and manuals. .. without this site's amazing closeup images and breakdown of Typex, Virtual Typex would not have been possible. My current home page of the last year!

GCHQ CyberChef .. GCHQ's CyberChef project team members on GitHub for not only creating an accurate Typex simulation for me to check against but especially for recording live audio from their working Typex for use in Virtual Typex!

Frode Weierud's .. for his work on breaking German Enigma ciphers for providing real German Enigma enciphered messages which can be deciphered and also Geoff Sullivan for helpful information and his work on simulations with the Crypto Simulation Group.


Creative Commons Licence
Virtual Typex by Virtual Colossus is licensed under a Creative Commons Attribution 4.0 International License.

Please feel free to use Virtual Typex to learn or teach others about the Typex machine and the work done at Bletchley Park. If you find it useful or if you have any feedback or ideas for making it easier to use or understand, please do let me know

Let me know what you think!

Have I got something wrong, it doesn't work quite correctly on your computer or maybe you just want to say hi - find me on Twitter or check my Facebook or Twitter pages

Martin Gillow