In this encryption lesson plan for KS3 computer science, students model the way that information is transmitted by the internet and try and protect their messages using different keys.

Encryption lesson learning objectives

• State what encryption means and describe why it is important
• Explain how information is transmitted over the internet
• Use simple encryption

Starter activity

Before revealing the objectives, write on the board the word ‘Noitpyrcne’ (encryption backwards) and ask students to work out what this lesson is all about.

When they have solved this, ask them to come up with a definition of the term ‘encryption’. Explain that it means putting information into a code so only the people for whom the information is intended can understand it. Discuss the need for encryption when sending information over the internet.

Main activity

Tell the class that they are going to model sending information over the internet. Divide the class up into groups of three and ask them to think of a team name.

Two students from each team sit at one end of the classroom and the remaining person at the opposite end. Tell them that they will be passing messages to each other.

Assign two teams as ‘eavesdroppers’. Their job is to try to intercept and read the messages.

Find the rest of the instructions in our download.

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