Teach Computing

Revision notes, activities, lesson plans, teaching ideas, and other resources for GCSE, A-Level, and IB Computer Science teachers and students.

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UK Computing Laws

This video from Computer Science Tutor covers the main UK computing laws re...

Wireless Networking (Wi-Fi, Security, and Hardware)

This video about wireless networking includes everything that is needed for...

Network topology videos

These four excellent videos from Computer Science tutor cover the four ma...

Network protocols

These four videos explain the main networking protocols that students are l...

Embedded Systems video

This short video is a good over of embedded systems, covering the main poin...

Representing Text in Binary

This video clearly explains the two main ways of representing text in binar...

Types of Malware

This video explains the various types of malware including viruses and troj...

Protecting against Malware

Following on from the Types of Malware video, this video explains technique...

Video: Network Security #1

This video gives an overview of the threats to networked computer systems, ...

Resources discount offer

3.4 Encryption

Click here for recommended Edexcel GCSE Computer Science textbooks.

3.4 Encryption

Encryption techniques

Encryption (National Codes Centre)

The National Codes Centre at Bletchley Park (who know a thing or two about ciphers) have comprehensive lesson plans, teacher's notes, and student activities for various types of encryption, from simple substitution ciphers (Caesar ciphers) through the infamous Enigma and Lorenz ciphers to modern day methods.

Updated: 2015-04-16


Very detailed but clear explanations of the various types of encryption systems, from simple substitution ciphers (Caesar ciphers) to modern public key encryption systems. The page also explains the types of attacks that can be performed against ciphers, such as known plaintext attacks and frequency analysis attacks. A variety of interactive applets held improve understanding.

Updated: 2015-04-19
Encryption systems

Braingle: Codes, Ciphers, Encryption and Cryptography

Braingle contains extensive notes on many different types of cipher systems from Caesar ciphers to four-square ciphers. There are dozens of examples and some interactives to help students understand the different ways plaintext can be encrypted. This could be a good site to support a lesson starter activity or extension activities for more advanced students who are interested in encryption systems.

Updated: 2015-04-25
Caesar cipher

Caesar cipher

A simple interactive that implements a basic Caesar cipher. One great use for this is to highlight just how weak Caesar ciphers are. By giving students examples of ciphertext and asking them to use this tool to break them, they should realise just how easy it is to perform a brute force attack.

Updated: 2017-10-24

Encryption and Caesar Cipher

An overview of the encryption process, from plain text to cipher text, along with a clear explanation of the Caesar cipher algorithm (which is sufficient for most GCSE Computer Science courses). A good revision resource.

Updated: 2018-02-17