Sunday, December 4, 2011

Bletchley Park Home Of The Codebreakers

Saturday, December 3rd - Bletchley, Buckinghamshire

In reviewing this entry I understand that you might call it "bookish"?  
Well, I'll leave it anyway.  Andy, who's forgotten more about computers than I'll ever know may find it interesting.  Doc's dad was in the Signal Corps, so he might get something out of it as well.

With nothing planned except a chicken and bacon baguette for lunch, I decided to walk down to the sprawling campus of Bletchley Park for a visit.
Bletchley Park was the home of the Government Code and Cypher School during World War II.  It's responsible for deciphering the German Enigma Machine captured during the sinking of the German submarine U-559. (fictionalized in Das Boot and U-571).

During the war, the mansion became the headquarters of the GC&CS.
It's a yard sale of architectural designs.

The mathmeticians and cyphers worked out of "huts" and "sheds" on-site.  Information was broken into its constituent parts and dispersed among the teams.
No individual or team understood how the information fit together, who they received their parcel from or who received it once their analysis was done.  80% of them were women called WREN's (Womens Royal e Naval Service) as the men were off to war.  Baskets might only go from one hut to another, but it could be London or Algiers for all the analysts knew.  A strict security code was enforced at Bletchley.

  • Do not talk at meals ...
  • Do not talk in the transport ...
  • Do not talk travelling ...
  • Do not talk in the billet ...
  • Do not talk by your own fireside ...
  • Be careful even in your Hut
  • First rule of Fight Club....

This decentralized structure is specifically the challenge in tackling groups like Al Qaeda, the Scallywags of the Home Guard (a really interesting story that includes Orson Welles), the French Resistance and even the early American Militia.  You can't chop the head off of the snake if you can't find it.
The Bletchley trust just received a £4.9M grant to restore the sheds.  Just in time.

Here's how it works:
The original message would be encrypted on a cypher machine, in this case a German Enigma.  The chances of guessing the cypher is 1 in 17,576.  However, the transmissions of the encrypted messages began with key setting code telling the receiver how to "key" his machine.

This machine has 4 encryption rolls with 26 stops on each, and it looks really cool.  That gives you a 1 in 456,976 of guessing the encryption code.


Radio transmissions were intercepted by post office and telecom recruits who were experts in Morse Code.  The "operators" might help short-cut the analysis if they identify a repeated pattern or message.  In fact much of the success at decoding secret massages is given to "lateral-thinking" where analysts were able to connect seemingly unrelated bits and pieces.

The transmission was then printed onto paper tape via a teletype machine. 

The possible key codes were entered into the Bombe which would discredit 17.5 thousand rotor settings, identifying the correct set in about 15 minutes.

The calculations were done electro-mechanically with vacuum tubes and relays and clockwork escapement mechanisms.
Why is it called a Bombe?  The best story is that the original hand cranked Polish design, when it had arrived at its solution, would drop a piece of the machine onto the floor.

Once the Bombe had calculated a possible key code.  The decryption machine, "Colosus" would actually read the paper tape through statistical analysis.

The tape was then transcribed.

and printed out.

The intelligence was dispersed to the mathmeticians and cyphers in the huts for Analysis.  Focused on "lateral thinkers", the GC&CS recruited cyphers through the Daily Telegram crossword.  Readers that could complete the crossword in 12 minutes or less were asked to contact in the paper in order to claim a prize.
The address to submit your entry was in fact a PO box (Number 1111 or 2222) for the GC&CS at Bletchley.

One group of analysts might identify a known person, maybe an electrical expert moving to North Africa.  Another hut might identify increased truck movements to North Africa.  Yet another might intercept technical specification for a RADAR installation.

The analyzed messages now coded "Ultra" would be dispatched via motorcycle messenger to London, or Cambridge, or another clandestine location in the woods.

HQ might deduce that Germany was building a new RADAR site.  The Allies would then wait for the installation to be built, almost operational and then go blow it up.  Just like the Death Star!

Steampunk this!  I want one of these, what do you think they cost?
Holy shit!  I just looked them up and a reproduction goes for $3-5k without the rotors (at $1-2k a piece)!
Another benefit to decyphering secret messages was being able to encrypt dis-information and send it across to misdirect and exhaust the enemy's resources.  Sort of like Fox News claiming that Obama's birth certificate is fake, I'm just saying.....

Alan Turing
Alan Turing, mathematician and computer scientist was the father of modern computing.  Before the war he helped develop the concept of computation, creating algorhythms for the analysis of complex systems (think of working out a Rubix cube mathmatically).
During WWII he worked for the Royal Navy at Bletchley in hut 8 where continued his work in computational analysis, including designing the Bombe and Colossus, (one of) the first digital computational machines. He led the Hut 8 team and spent most of his time either in pure research or teaching other mathematicians and cyphers.
After the war he went to Manchester where they created the first "computer" with stored memory.

After reporting a break-in at his home by a former male lover to police, Turing was tried and convicted of indecency.  In 1952 he choose to be chemically castrated instead of  prison.  In addition, he lost his security clearance and was barred from further engagement with the GC&CS.
This sculpture is made from stacked slate stone (something to interest Roy if he's reading).

Turing comitted suicide in 1954.

In 2009 Prime Minister Gordon Brown publicly appologized for Turings prosecution;
 "So on behalf of the British government, and all those who live freely thanks to Alan's work I am very proud to say: we're sorry, you deserved so much better".

Do you know who else worked for the Royal Navy at Bletchley during the War?  Ian Fleming!
You do know who Ian Fleming is don't you?  Author, spies, fantastic machines.........?


Ian Fleming!  He wrote Chitty Chitty Bang Bang!
Wonder where he got some of his fantastic ideas from?

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