If you like reading books on a screen (paper – who needs paper?) and don’t want to carry tons of real books, then go ahead and read it in your browser right away.

The ePaper is hosted on issuu.com, so you can read it directly online without having to download anything. If you have an account there, you can add it to your favourites.

PDF Format

Download the book in the common Portable Document Format (PDF) for your eReader and for printing-at-home. You might need a software like Adobe Acrobat to open it on your computer.

There are two versions available – a high-res file for printing (with better image quality) and a low-res file for a faster download (e.g. for mobile devices).

ENIGMA keyboard
Bletchley Park

eReader Formats


The .iBooks version is designed for the iBooks app of the Apple iPad (works also on a Macbook). It is optimised for reading both in portrait and landscape mode. Please note that this version has been created in 2012 and has not been updated since.

.mobi and .ePUB

These versions are optimized for your Kindle device and other eReaders. Please note that these versions were created in 2012 (according to the standards back then) and have not been updated since.