Codebreakers: Bletchley Park's Lost Heroes

Most people have at least heard of Bletchley Park, the UK's codebreaking centre during World War II. Even if you haven't heard of the place, you've probably at least heard the name of the most famous code to be cracked by them: Enigma.

This BBC program details the history behind an even tougher code that is less well known, but appears to have been just as vital to the war effort as deciphering Enigma-encoded messages. The story is also one of the people behind the scenes, especially two mathematicians whose contributions, although invaluable, have gone largely unrecognised by history.

The Lost Heroes of the title are Bill Tutte and Tommy Flowers, both of whom made significant steps in the race to understand and decode messages sent by Nazi forces: Tutte made great strides in understanding with regards to machine-based ciphers, and Flowers designed and developed the world's first electronic computer, Colossus, in an effort to speed up the process by which messages were decoded.

Timewatch - Code-breakers: Bletchley Park's Lost Heroes: 

https://www.bbc.co.uk/iplayer/episode/b016ltm0/timewatch-codebreakers-bletchley-parks-lost-heroes