New
New
Year 8

Turing's mug cryptography challenge

I can decode binary messages to crack a hidden code.

New
New
Year 8

Turing's mug cryptography challenge

I can decode binary messages to crack a hidden code.

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Lesson details

Key learning points

  1. Encryption is the process of converting a message from plain text into cipher text.
  2. Encryption is used to protect data.
  3. During WWII, German officers used a special device called an Enigma machine to encrypt all of their communications.
  4. During World War II, Alan Turing's secret work at Bletchley Park was central to decrypting German communications.

Keywords

  • Encryption - the process of converting information or data into an unreadable format called cipher text

  • Decrypting - the process of converting encrypted data (cipher text) back into its original, readable format called plain text

Common misconception

Once encrypted, a message cannot be decrypted.

A message can be encrypted and decrypted multiple times, this happens frequently during digital communications.


To help you plan your year 8 computing lesson on: Turing's mug cryptography challenge, download all teaching resources for free and adapt to suit your pupils' needs...

This lesson could lead onto some research about the Enigma machine, or you could get learners to create their own codes to challenge each other.
Teacher tip

Equipment

Pupils may need access to the additional material for this lesson.

Licence

This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

Lesson video

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Prior knowledge starter quiz

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6 Questions

Q1.
Which of these is the largest unit of digital information?

kilobyte
megabyte
byte
Correct answer: gigabyte

Q2.
How many bits are there in one byte?

Correct Answer: 8, eight

Q3.
What does the prefix ‘kilo-’ mean in kilobyte?

10
100
Correct answer: 1,000
10,000

Q4.
Which of the following is NOT a type of digital data?

Correct answer: plant
text
sound
image

Q5.
Match each unit to its description:

Correct Answer:bit,smallest unit of data

smallest unit of data

Correct Answer:byte,8 bits

8 bits

Correct Answer:kilobyte,1,000 bytes

1,000 bytes

Correct Answer:megabyte,1,000,000 bytes

1,000,000 bytes

Q6.
What is the decimal value of the binary number 11100?

Correct Answer: 28, twenty-eight, twenty eight

Assessment exit quiz

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6 Questions

Q1.
Who played a key role in breaking the German codes during WWII?

Charles Babbage
Correct answer: Alan Turing
Tim Berners-Lee
Ada Lovelace

Q2.
Which of these is a true statement about encryption?

Once encrypted, a message can never be decrypted.
Encryption always uses numbers only.
Only computers can encrypt messages.
Correct answer: Encryption and decryption can happen many times.

Q3.
What is the name for the process of converting plain text into cipher text?

Correct Answer: Encryption, encrypting, encrypt

Q4.
Match each term to its meaning:

Correct Answer:encryption,the process of making data unreadable

the process of making data unreadable

Correct Answer:decryption,the process of making data readable again

the process of making data readable again

Correct Answer:cipher text,the unreadable version of a message

the unreadable version of a message

Correct Answer:plain text,the original, readable message

the original, readable message

Q5.
Which of these is an example of using encryption in everyday life?

writing a diary
Correct answer: sending a coded message through a messaging app
drawing a picture
reading a book

Q6.
Place these steps in order for sending an encrypted message:

1 - write the message
2 - encrypt the message
3 - send the message
4 - decrypt the message

Additional material

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