The hacking of Hitler's Blackberry

BBC's Code-Breakers: Bletchley Park's lost heroes (broadcast yesterday & on BBC Iplayer).
Excellent documentary on how the code-breakers cracked the Lorenz cipher which used radio broadcasts to send encrypted information between units of the German war-time forces in a similar fashion to encrypted traffic on the modern-day internet. The veil of secrecy upon how this done that hid Alan Turing's contributions (until recently) to code-breaking also hid the achievements of the two heroes of this story; A mathematician called Bill Tutte and a GPO engineer called Tommy Flowers.

The big break came when a 4000 character message was re-transmitted with the same key. Linguistically-talented code-breakers were able to get insights into the code but not enough to routinely break the code.
It was then passed to Tutte, who, in a classic mathematicians approach, looked for patterns which enabled him to deduce the number of spokes on the wheels of the Lorenz machine.
Information gained from this discovery enabled the allies to warn the Russians about an assault on the lines (The battle of Kursk) which was as the Russians called it 'the turning of the tide' on this front.

This methodology still required a lot of manual effort and whilst an electro-mechanical device (nick-named 'Heath Robinson') was devised it needed to be faster and more reliable. The stage was set for 'Colossus' devised by Tutte which was the world's first semi-programmable electronic computer (Pre-dating Eniac)and was about five times faster than it's predecessor. This helped with breaking the code but still relied upon people for the latter stages.
Colossus made major contributions to the success of the D-day invasion and enabled the allies to get into Hitler's head. His responses to military situations were not like normal military commanders and so the Allies had to think like Hitler.
There are two major ironies to this story:
1) The Nazis distrusted people and placed their trust in the machines and the idea that they could not be compromised - a warning for today's society maybe?
2) Bletchley had many key people who would not have been used by the Nazis (Jews, gays (like Turing) and intellectuals who tended to isolate themselves from mainstream society) - a strong pointer to the benefits of Diversity. Another example was the key role of the army of women employed to listen to and accurately transcribe the intercepted (and encrypted) German transmissions i.e. the data gatherers for the mathematicians.

It is noticeable that both men were examples of the benefits of the scholarship system which enabled them to make significant contributions to society despite their unprivileged backgrounds.
Both Tutte and Flowers were restricted about communicating their war-time roles in peace-time.
Bill Tutte made significant contributions to Graph Theory and some of his work assisted in the proof of the four-colour theorem (used to determine positioning of mobile phone transmitters) and later became a Fellow of the Royal Society.
All in all, I found this to be an excellent programme.