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Unit of work

Introduction to cryptography

Computational thinking, History, Programming | MakeCode, Python | 11-14 yrs

In this series of 3 lessons aimed at pupils in the first year of secondary school (KS3 Year 7 in England), students learn about cryptography and undertaking practical unplugged activities to develop their logical reasoning and problem-solving skills.

They write algorithms for a Caesar cipher and are introduced to writing Caesar ciphers in text-based programming using JavaScript and Python.

This unit forms the second part of the cyber security unit, though it can be used on its own and can be a good introduction to text-based programming, or a way to extend existing knowledge.

The lesson sequence comprises 3 lessons of approx. 60 minutes:

  1. Introducing cryptography today and in history (World War Two)
  2. Caesar cipher algorithms unplugged activity
  3. Creating Caesar cipher programs with text-based programming

Learning objectives

  • can understand and apply the fundamental principles & concepts of computer science (logic, abstraction, algorithms, real world problem analysis and problem solving).
  • practical experience of writing computer programs to solve problems.
  • are responsible, competent, confident and creative users of information and communication technology.

Additional skills

Problem-solving, collaboration, critical thinking, creative thinking, prototyping, presenting, researching.

You will need

Downloadable resources:

  • Lesson plan
  • Lesson slides
  • Student handouts
  • HEX files

Other resources:

  • card
  • paper - large sheets
  • paper - rough
  • paper fasteners / split pins
  • pens
  • scissors
  • student work from previous lesson

Lessons created in partnership with Nominet