HOW would you crack an uncrackable code?

That was the challenge faced by the workers of Bletchley Park, Britain’s top-secret code-cracking operation, at the height of the Second World War.

Every day, messages from the German military were being intercepted and poured over by thousands of codebreakers; every date and detail they could decipher taking them one step closer to winning the war. What stood in their way was Nazi Germany’s preferred mode of communication: the Enigma code.

The Enigma code was devilishly indecipherable and contained everything from weather reports to the locations of warships. In order to read it the Allied codebreakers needed to have another Enigma machine set up in exactly the same way as the one that created the code. The Enigma machine looked like an odd typewriter, with one set of keys to type a message, and a panel above designed to light up to show the new encrypted message.

For example, if you pressed the letter ‘T’ you may see ‘F’ light up. If you removed the cover and looked closer you would see a mess of wires plugged into different sockets (one for each letter of the alphabet) as well as six rotors whirring and clunking into place with each letter you type. These scramble your message further. The next time you type ‘T’ it is ‘V’ that lights up. With every possible combination of rotors, numbers and wires the Enigma machine had 150 billion billion states and those states were being changed every day.

Originally, Bletchley Park was home to about 186 carefully-selected employees. They were academics with a talent for maths and thinking outside the box, including Dillwyn ‘Dilly’ Knox and Alan Turing. However, as the war stretched on it was clear more manpower was needed to run this operation. The issue was that all the manpower was on the frontline. This is when Bletchley Park welcomed some of its lesser known clerks and codebreakers from an unexpected source: debutantes.

These young women were mostly likely hired first because their families belonged to the upper-class inner circle. However, many of them also had the right skills for the job: they could speak German. One particular codebreaker, Jane Fawcett, had learnt German in Zurich after leaving the Royal Ballet School, being deemed ‘too tall’ to have a career as a dancer.

She was living in a ski resort in St Moritz when a friend invited her to apply for Bletchley Park.

Another, Pamela Rose, even turned down her first role on the West End to join the effort to

crack the German codes as she had learned German from her mother.

By 1941, the conscription of women was introduced and more and more young women from all over Britain were brought into the Government Code and Cypher School at Bletchley Park. Soon over seventy-five per cent of the workers there were female, most of them having just turned eighteen and away from home for the very first time.

They worked long hours in poorly-ventilated rooms, some earning as little as 75p a week.

However, their working conditions did not deter them from their task.

Their deciphering led to the sinking of the Bismarck and some of the first intelligence of the Holocaust, a message intercepted by Betty Webb; she was aged 18 at the time.

The women of Bletchley Park were solely responsible for operating the Bombe machine, an invention of Alan Turing and Gordon Welchman designed to whirr through the 150 billion billion possible combinations of the Enigma machine’s code.

Each machine had 180 drums equivalent to 36 Enigma machines working in tandem and was so loud that they often caused permanent hearing damage to their operators.

When the war had finally ended, these young women returned home, unable to tell a single soul about where they were or what they did until 1970 when the secrecy surrounding their work was finally lifted. Now we understand the role these incredible women played in cracking one of the first codes produced by a machine and shortening the war by two years.

In 2020, we need coders more than ever, to crack codes and to write them, as our world becomes more and more invested in digital technology.

Why not see if you have what it takes to be just like the women of Bletchley Park by trying to crack the code set by Glasgow Science Centre as part of our GSCAtHome series on social media.