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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Device specifications

Device Specifications is a simple site with a huge database of smart phones...

Smart phone specs explained

This excellent site is a detailed guide to smart phone specifications, expl...

Software as a Service (Saas)

This short video gives an overview of Software as a Service (SaaS), which s...

Amazon EC2 - Elastic Cloud Server

Amazon Elastic Cloud (Amazon EC) is a good example of Infrastructure as a S...

Changeover notes

IGCSE ICT provide short but clear notes and diagrams covering the different...

CommandPoint CAD

CommandPoint by Northrop Grumman offers a range of CAD systems for various ...

CAD+911 System

TriTech Software Systems is a company that specialises in Computer Aided Di...

London Ambulance CAD failure

The 1992 London Ambulance Service CAD failure is probably the most notoriou...

Washington State 911 Failure

A 911 emergency telephone system in Washington State and Oregon shut down f...

Resources discount offer

1.6 Security, privacy and data integrity

The resources here cover the basics of data security and integrity. A-Level students also study computer security, including encryption techniques and malware, in section 3.5 of the Advanced Theory paper (paper 3). Click here for recommended Cambridge A-Level Computer Science textbooks.

1.6.1 Data Security

Password security

Secure passwords

CommonCraft popularised the paper-and-marker pen style of video explanation, and some of their original videos are still the best. Secure Passwords Explained by CommonCraft does exactly as you might expect.

Microsoft's Password Checker and the site How Secure is my Password? offer quick ways to see how the complexity of a password significantly alters how easy it is to crack: for obvious reasons it is probably better to use these sites with imaginary passwords rather than your real passwords!


Updated: 2015-04-10
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
Data security

Examples of database security problems

The news articles below cover some of the major risks of malicious actions such as hacking or malware. Myriad examples of these problems exist (and new ones seem to appear every few weeks), but the examples below highlight some of the more famous cases (and the greatest losses).


Updated: 2015-04-18
Encryption

Encryption

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

1.6.2 Data Integrity

Network error detection

Parity and Checksums activity

The card flip 'magic' game is a great idea from Computer Science Unplugged. The teacher sets up a grid of black/white cards and asks students to turn over one card without the teacher seeing. Using parity rules, the teacher is able to 'magically' determine which card the students turned over. This is a really fun game which demonstrates how simple techniques like odd/even partity can be used to solve significant problems.

The Computer Science Unplugged page has a range of support material: instructions for teachers, videos of the activity being performed, and a PDF download with extension activities and details about check digits in ISBNs.


Updated: 2015-05-02

Parity bit game

This interactive online game is like a digital version of the parity card game. Students are presented with an 8x8 grid. They must first set the parity bits correctly using even parity. The computer will then scramble the grid and change a single bit, which students must identify using the rules of parity.


Updated: 2015-05-27