Key Stage 5 & FE

Codes & Ciphers

On-site or outreach

From Ancient Greece to the modern day, people have been using increasingly complex codes and ciphers with the intention of communicating secretly and keeping information secure. Enigma was one such cipher. Students will enjoy the rare opportunity to use a genuine Enigma machine as well as encountering a range of historical codes and ciphers as they work together to decipher messages in order to solve a puzzle. This session includes an Enigma machine demonstration.

During this session students will:

• Increase their knowledge of codes and ciphers and their uses throughout history.

• Develop their understanding of the role that ciphers played during WW2, with specific reference to the Enigma machine and the wider operations of Bletchley Park.

• Use and develop team working, problem-solving and mathematical thinking skills, applying them to a practical codebreaking task.

Subject Focus: Maths,

Additional curriculum links: History, Computing

Story of Enigma

On-site or outreach

The German Military believed the Enigma cipher was unbreakable. They were wrong, but the Codebreakers were only able to break Enigma because of human error, complacency and predictable message formats. Students will examine a genuine Enigma machine to figure out for themselves what made Enigma such an effective cipher at the time and calculate the exact number of possible key settings per message. This session includes an Enigma machine demonstration.

During this session students will:

• Learn about and understand the operation, use and purpose of Enigma machines in WW2.

• Work together to develop and apply their mathematical skills and knowledge to calculate the number of possible key settings per message for a standard army Enigma machine.

Subject Focus: Maths

Additional curriculum links: History

Breaking Lorenz

On-site or outreach

More effective but less well-known than the iconic Enigma machine, Lorenz was the cipher of the German High Command.

Fiendishly difficult, the Lorenz cipher seemed impossible to break, but Bletchley Park Codebreaker John Tiltman’s inspired breakthrough paved the way for other codebreakers to unlock its secrets. His thought process is laid bare, and students will engage with a series of tasks of increasing complexity designed to give them a full understanding of Tiltman’s break and some of the secrets of this machine, including its use of binary operations to generate many key settings that dwarfed that of Enigma.

During this session students will:

• Develop their knowledge and understanding of ciphers used in the past including those during WW2

• Understand the number of possible settings for a Lorenz machine and come to recognise the scale of the problem for Codebreakers in WW2

• Understand how a key logical step contributed to the breaking of a WW2 cipher, using ideas related to binary addition, the XOR operation and common language patterns

• Work through a problem-solving procedure collaboratively based on real historical events

Subject Focus: Computing

Additional curriculum links: History, Maths

This session does not include an Enigma machine demonstration.

Interception to Intelligence: Battle of the Atlantic

On-site

It is 1941 and the Battle of the Atlantic is at its height. Numerous convoys of essential supplies are being sunk by German Wolf packs and Britain is close to surrender. In the role of codebreakers students will intercept, decipher and translate German Naval communications in order to plan a strategy to get the next convoy safely to Liverpool. This session includes an Enigma machine demonstration.

During this session students will:

• Develop their knowledge and understanding of WW2 events and the role of Bletchley Park in the Battle of the Atlantic.

• Briefly describe the process of decryption at Bletchley Park, from when a message is first intercepted until the intelligence is used.

• Apply team working, problem-solving and strategic thinking skills to obtain and apply scenario-based intelligence.

Subject Focus: History

Additional curriculum links: Geography, Maths

Interception to Intelligence: D-Day

On-site

It is the early hours of 6th June 1944. Weather prevented Operation Overlord commencing in the early hours of June 5th so today is the best, and perhaps last, chance the Allies have of beginning the invasion of German-occupied Western Europe. Numerous deception plans have been put into place to fool the enemy and protect Allied troops. In the role of codebreakers students will intercept and decipher German communications in order to decide if the deception plans have been successful and whether it is safe to proceed with the invasion. This session includes an Enigma machine demonstration.

During this session students will:

• Develop their knowledge and understanding of WW2 events and the role of Bletchley Park in the D-Day landings.

• Briefly describe the process of decryption at Bletchley Park, from when a message is first intercepted until the intelligence is used.

• Apply team working, problem-solving and strategic thinking skills to obtain and apply scenario-based intelligence.

Subject Focus: History

Additional curriculum links: Geography, Maths

Past, Present and Future Encryption

On-site and outreach

This workshop has been designed for KS5 students studying A-Level Computer Science and links to the AQA, OCR and Cambridge syllabuses. It is also suitable for students studying BTEC Computer Science Level 3.

Throughout history people have used cryptography to keep data secret. But as Bletchley Park’s wartime work proves, seemingly ‘unbreakable’ encryption systems can be broken. So how can computer scientists use cryptography to keep data safe?

Through discussion, interactive demonstrations and practical activities, students will:

• Consider the types of cryptography used by Germany during World War 2 and the weakness in German ciphers.

• Learn the principles that have led to secure modern-day encryption.

• Send a message using the symmetrical and asymmetrical methods used by modern end-to-end encrypted messaging services.

• Discuss the future of cryptography with quantum computing on the horizon.

Subject Focus: A Level Computer Science and BTEC Computer Science Level 3

Additional curriculum links: History, Maths

This session does not include an Enigma machine demonstration.