KS3 Computing Lessons
Welcome! 👋
This site contains hands-on computing lessons designed for Key Stage 3 students (ages 11-14).
Learn about how encryption and hashing keep your data safe online through fun, interactive activities!
Available Lessons
🔐 Encryption vs Hashing
Learn the difference between encryption (lock & unlock) and hashing (lock only). Understand why both are important for keeping your data safe.
Learning objectives: - Explain the difference between encryption and hashing - Describe when each should be used to protect data - Give real-world examples of both
📖 Book Cipher Encryption
Try encryption yourself using a book cipher! Send secret messages to your classmates that only they can decode.
What you’ll do: - Encrypt messages using a shared “key” (a book) - Swap encrypted messages with partners - Decrypt messages and discover why keys are important
🔒 Password Hashing
Discover how websites protect your passwords using one-way hashing. Use Python to see hashing in action!
What you’ll learn: - Why websites never store your real password - How hashing is a one-way process - Why tiny changes create completely different hashes - How this protects you from hackers
🔐 Encryption
Learn how encryption works using a Caesar cipher in Python! Discover how keys work and why encryption is different from hashing.
What you’ll learn: - How to encrypt and decrypt messages using a key - Why encryption is a two-way process (unlike hashing) - How keys protect your messages from eavesdroppers - Real-world examples of encryption protecting your data
Getting Started
- Start with the theory: Read Encryption vs Hashing first
- Try the practicals: Work through the hands-on activities
- Discuss: Use the discussion questions to explore the concepts deeper
- Challenge yourself: Try the optional stretch activities
Why is this important?
Every day you use encryption and hashing without realizing it:
- 🌐 HTTPS websites use encryption to protect your browsing
- 🔐 Password logins use hashing to keep accounts secure
- 💬 Messaging apps use encryption for private conversations
- 💳 Online shopping uses encryption to protect payment details
Understanding these concepts helps you: - Stay safe online - Make better security decisions - Understand how technology protects your privacy - Build a foundation for cybersecurity careers
Ready to start learning? Click on any lesson above to begin! 🚀