The Bletchley Park Challenge


Learning is a large part of what happens at Bletchley Park. Visitors may not realise that our extensive education department welcomes schools, colleges and universities nearly every day. In our dedicated facility young people have the opportunity to learn about the history of cryptography, from the Caesar (or ‘shift’) Cipher through to today’s dual-key asymmetric techniques that we use every day of our lives, often without realising it.

As more and more children have access to smartphones and tablets, we have an opportunity to follow-up on these sessions with apps. Additionally, using mobile apps as an education medium means we can reach others that are not part of the education programme. Often a visit to Bletchley Park can be a little technical for the younger visitors. Sure they enjoy the toy museum and the model railways but often the ‘codes’ can go right over their heads. Wouldn’t it be great if we could appeal to them more at their level and help explain how codes and ciphers were used to keep secrets.

The Challenge

So, here’s what I’d like to see:
Devise a solution whereby one or more users can send ‘secret’ messages to each other using a dedicated BP-themed app. The cipher employed should be simple enough to be explainable and demonstrable to the user. For instance, a Caesar cipher (shifting the alphabet n places to the left or right) is simple to understand yet an effective cipher.

  • A form of communication network will be required. Use email or devise your own service as appropriate.
  • A user should be able to set the parameters for the cipher (as required by the cipher used) and encrypt a message
  • The message should be transmittable to another user
  • The recipient should be able to ‘guess’ the settings or the message content (or partial content – think Hangman) but not be told them, so if the sender wishes, they can reveal the setting or message.

What I envisage are parents being able to provide their children with the app at BP (although geo-dependancy would not be required) and the little ‘uns can have fun throughout the day sending secret messages to each other or their parents. In the process, the children learn a little about codes and are entertained.

The above is only a suggestion of how such an app could operate. Credit will be given for original thinking and ingenuity! It doesn’t have to be a Caesar cipher and indeed could be any form of game.

The only requirement is that it reflects on Bletchley Park in style.

If you have any questions, drop me a line via @mrpjevans on Twitter.

The Prizes

T-shirts for each member of the winning team from the Bletchley Park store (exact style yet to be determined).