The

The From the home of the co-breakers and the birthplace of modern computing, this is the Bletchley Park podcast.

Hello, this is M.C. Fontaine welcoming you to another Bletchley Park Podcast Extra.

This week we bring you a little more from the MythBusters event.

Best-selling author of Michael Smith was joined by the official GCHQ historian

and also making a rare public appearance, former Bletchley Park Code-breaker and later GCHQ director, Sir Arthur Bonsel.

What I want to do now is just a quick run for you.

Enigma was first produced by a German called Cherbius in 1921. It was a commercial machine. It was

designed actually for companies and banks originally, but the German Navy took it up in

1926, German army in 1928. Leufwebaud didn't take it up until 1935.

The Polish mathematicians broke the system in 1933.

They've been in touch with the French intelligence who had supplied them with a user handbook.

And the great thing about this user handbook was that they had a message in German and then

on the Liege, Enigma equivalent, and it had actually been done on an enigma machine.

So that gave the Poles a great way into the system.

They also, of course, had their own commercial system, theigma machine which they bought, and they also had, also provided by a French spy, settings for two days.

That shouldn't mean that it takes away from what was then an incredible achievement.

They broke it purely in a mathematical fashion. And when he heard about this,

Dennis then the head of GC&CS decided to start recruiting mathematicians like Turing, like

Welshman, and eventually people like Bill Tiltoswell, of course, Dilly Knox. This man doesn't get

any way enough credit, and actually

Kim Filby in My Silent War in 1968 revealed that Dilly Knox had broken the German

...