Our modern-day Enigma challenge

Last Updated: 24 Jun 2016
Our code-breaking predecessors at Bletchley Park were famed for cracking Enigma, providing valuable intelligence during WWII.  Today, we use our Enigma machines for education.

At a variety of events around the country we have offered people the chance to encrypt their own message on a real Enigma machine, and send it to our team of experts who then attempt to decrypt it.

We launched these Enigma Challenges in 2012, the centenary of the birth of Alan Turing, one of the mathematicians behind the Allied success against Enigma.  Along with volunteers from Bletchley Park, we re-enacted the process of decrypting messages. Since then, we have taken a machine to various events across the country, including Manchester where Turing worked at the Victoria University from 1948.


A typewriter-like key is being pressed, causing a different letter to be lit up on the lightboard
©GCHQ 2016


Our most recent challenge took place at this year’s Times Cheltenham Science Festival, #CheltSciFest.  At our stand in the Discover Zone, members of the public used the Enigma to type out a message, turning their words into encrypted text. Blending the new with the old, they then tweeted the encrypted secret message to the @EnigmaChallenge account.  

GCHQ staff hidden elsewhere at the Science Festival picked up the secret message from Twitter and set to work decoding it.  They used Cryptoy, a GCHQ app that mimics an Enigma machine.  By mirroring the real Enigma settings on Cryptoy, the encrypted messages were easily turned back into English by the GCHQ team.     

Below you will see one of the encrypted messages sent from @TH_Enigma and what it revealed when the @EnigmaChallenge team decoded it - a familiar message for those who have discovered us on @gchq.


QUFKX SZBIB was decrypted using the Cryptoy app to HELLO WORLD
©GCHQ 2016


Results from our previous challenges are posted on @EnigmaChallenge so you can see how we did.  Cryptoy is available as a free download for your Android tablet from Google Play.

Late in the evening, the team at the festival decrypted the final message:


©GCHQ 2016


And with that thought we went home to prepare for the next Enigma challenge.