On Friday 21^st February, our Fettes College Maths, History and Computer Science departments were joined by 60 pupils from 4 visiting Prep and Senior schools to take part in our Codebreaking Day 2020. 

The day kicked off with a presentation from Dr James Grime who introduced us to the secret history of codes and codebreaking, which included a rare chance to see a genuine Second World War Enigma machine. Dr Grime also regaled the story of who the mathematicians were that broke Enigma and how they did it. Afterwards, the pupils were given the opportunity to learn more in small group sessions.

The pupils were then split into groups and given the opportunity to take part in a host of different activities.

The Maths session allowed the students to become codebreakers for themselves. They used the knowledge they gained from Dr Grime to break some codes, including the Pigpen Cipher, the Caesar Shift, the Affine Cipher, frequency analysis and even a mini pocket Enigma.

The History session pupils were introduced to the concept of human intelligence and the role of individuals in codebreaking and code making. They were tasked with finding out more about notorious spies but in order to gather the intel they needed to break a series of codes. There were also some spies in our midst and one task required students to work out who the KGB agent was; however, they also risked giving away secrets to MI6. Students learnt about Mata Hari, the Culper Ring, the Rosenbergs, the Cambridge Spies and even Casanova. It was an active session and complimented the codebreaking knowledge they had gathered throughout the day.

Finally our Head of Computer Science lead a session on steganography with students looking at how to hide messages in plain sight.  They looked at how messages had been hidden in the past including using lemon juice as invisible ink and even being written on silk, scrunched into a ball, dipped in wax and swallowed! They then created pictures with hidden messages inside. In the process they looked at how computers store numbers and can also use these numbers to represent letters.  By the end students had produced a variety of images from sunsets, and trees to rockets and dragons, but secretly containing messages of up to 20 characters.

The students left with their own puzzles to take away and hopefully with a little more insight into the world of coding.

Thank you to all of our visiting students, we had a blast!