The world of cyphers, code breaking and Enigma machines came to Farlington from Bletchley Park recently. Girls from Year 6 to the Upper Sixth were given a fascinating insight into encryption and the work of the World War II code breakers by Tom Briggs, Bletchley’s Education Officer.
Early examples of encryption such as wax tablets and hidden tattoos introduced the students to the basic premise of encoding that both conceiver and recipient need to understand the key to the code. Book codes were explained which used the letter, line and page of a particular book to convey secret messages. They were also shown the televised interview of US pilot Jeremiah Denton, the Vietnamese prisoner of war, who blinked the word ‘torture’ using Morse code whilst speaking with his Vietnamese captors. Before the workings of the Enigma machine were explained, the Caesar and Vigenere ciphers were also outlined, along with frequency analysis.
Originally developed privately in Germany in the 1920’s for the banking sector, the Enigma machine looks like an oversized typewriter. Enter the first letter of your message on the keyboard and a letter lights up showing what it has replaced within the encrypted message. Inside the box, the system is built around three physical rotors. Each takes in a letter and outputs it as a different one. That letter passes through all three rotors, bounces off a “reflector” at the end, and passes back through all three rotors in the other direction. The receiver needed to know the exact settings of these rotors in order to reconstitute the coded text
Hannah Carleton-Jepson and Kira Hyde from Year 9 said, “An expert from Bletchley Park came to school to talk to us about code breaking and the Enigma machine. We went into the day with little knowledge of what went on during WWII at Bletchley, but throughout the talk we began to realise how important that work was, and without it we may not have won the war. Learning how much of a secret everything had to be kept, and just how complicated the code breaking process was, we were really able to put ourselves in the position of all the people working at Bletchley during the War.
“We were given a background to codes and ciphers and even given one to break ourselves. We looked in detail at the Caesar cipher – using the alphabet in different ways in order to encrypt a secret message, and also how to decrypt them. The workings of the Enigma machine were explained, which had over a cinquillion different settings which had to be broken every single day by the people at Bletchley!
“Now Bletchley Park has been turned into a museum and is only closed four days a year, and we definitely will be taking a trip up there soon. The day was very interesting and we can now appreciate the hard work that went on during WWII.”
The day organised by Claudine Maude, Farlington’s Lower School Maths Co-ordinator. She said, “The aim of the day was for the students to see first-hand some interesting and practical applications of mathematics, as well as to learn a little about British history.
“As a Maths teacher I often get asked ‘when will I ever need to know this?’ and my response is always ‘you never know what you will end up doing in the future’ and this seemed an appropriate example.
“We are very grateful to Farlington’s PTA who funded this workshop which allowed the girls to see an Enigma machine in real life and gain an insight into the practical workings of mathematics outside of the curriculum.”