• 2017.09.29
  • Bletchley Park, a solved Enigma
To the north west of the capital, about a hundred miles away, is Bletchley.
Easily reachable by train, Bletchley is a small English village without much appeal.
So why is this place so important and so famous?
Basically because it is a key place for the history of Europe in the twentieth century.
If you've watched “The Imitation Game,” you know what I'm talking about.
In Bletchley is Bletchley Park, chosen by the British Army during World War II as a top-secret place where the best of the best English experts on encryptions were trying to decipher the messages of the Nazis and thus know in advance the moves of their enemies.
Since the military secret has been removed, Bletchley Park has now become a beautiful museum where it is possible to retrace the incredible past of this place that could otherwise be forgotten by most and only known to historians.

Bletchley Park building

The visitor's experience is always at the centre of the attention here, both demonstration panels and prepared guides allow you ‘to breathe a ‘40s atmosphere’ and one can also try to learn more about cryptography by trying to decipher ‘secret codes.’
Although “The Imitation Game” portrays a different reality, there were many things happening in this place in the ‘40s and many were the people responsible to decipher the encrypted messages (not just one).
First of all, some experts intercepted the Nazi messages, often communicated in Morse code, and transcribed these messages into letters.
Once the messages were gathered and typed, they were moved to Building 3, where they had to be deciphered and translated from German so that they could make sense in English.
Finally, in Building 6, the decrypted message was rewritten so that it could be handed down to those on duty in the army.

Due to the nature of these information, decrypting a message had to remain a secret and it is true that Alan Turing played a decisive role, because the realization of his machine allowed the Allies to own a powerful espionage instrument since it made things quicker.
But the importance of his machine became clearer when, in Bletchley Park, he discovered how to understand Enigma.
Enigma was a secret ‘language’ that the Nazi army used to encrypt every message: although this wording seemed harmless, it was a concentration of diabolical strategy. At Bletchley Park Enigma is presented everywhere, in all its models.


It is important to understand what the British army had to deal with and how much information they had to collect before winning over it.
Enigma is a two-key typewriter whose messages come out on a sheet of paper, always with a 5-letter combination.
The top keyboard is used because when you press a key in the lower one, the actual letter you are typing lights up. There are three rotors at the top, each of which has 26 possible positions on which it can be set.
This means that, at the beginning, Enigma has 26 x 26 x 26 possible combinations for a total of 17576 different ones.
Basically if you type an A, the key is redirected to another letter depending on the position on which the rotors are set.
But the original Enigma typewriter was even more complicated than that because when you pressed an Enigma key, the letter that came out did not only depend on the position of the rotor, but also on the rings that adjusted its wires.
From the initial input, which could be for example an A, we could get to a G, but this passage was electromagnetically filtered by the combined action of the rotor and the electric wires.
We said that only through the initial position of the rotors we could get 17576 combinations.
Now, with the combined action of electricity, this figure rises. How much?
There were millions of possibilities.

Many typists worked here

With a full team of typists working day and night trying to decode the message, it would have taken a million years to solve this.
And since the Nazis changed the code at 6am every morning, we clearly understand how big this task was.
Every day, from 6am to midnight, Turing’s Enigma machine worked to decipher and collect combinations, storing millions of tabs containing words and corresponding letters.
Many historians estimated that World War II has been shortened by a couple of years thanks to the work done here at Bletchley Park by Turing and his fellow experts.
Personally I can barely remember the PIN code of my bank card so I can tell you that this place is fascinating although the science behind it is rather complicated and hard to get for most.

The Turing Bombe


  • GianFranco Belloli
  • AgeMouse(NEZUMI)
  • GenderMale
  • Jobblogger/musician

I moved to London over 2 years ago but only last year I started writing for a local newsletter for Expats in London telling about my experience in this big city and giving advice to newcomers. London is a very dynamic city and has a lot for everyone but it’s important to have a local point of view to navigate it without getting lost. Let me be your guide to hidden London!

View a list of GianFranco Belloli's

What's New


What's New