Utility software
Encryption Software
Encryption software is a utility that scrambles data so that nobody can understand it without the correct key. The scrambled version is what gets stored or sent, so anyone who comes across it sees only a meaningless jumble.
How encryption software works
The software follows an algorithm — a fixed set of steps — and uses a key, a value that controls exactly how the scrambling happens. Together they turn readable data into scrambled data; to get the original back, the scrambled data must be decrypted, which only works with the correct key.
For example, a quiz club stores the answers to a competition that is still running. Encrypted, the answer list becomes a jumble of odd characters. A member who has the key decrypts it and reads the answers; anyone else who opens the file sees the jumble and learns nothing.
Why it is needed
Computers store and send data that must be kept away from unauthorised people, and the answer list is one example. If the data is intercepted on its way across a network, or the device holding it is lost or stolen, encryption means it is useless to whoever has it: without the key the contents cannot be understood or used.
| What encryption does | What it does not do |
|---|---|
| Scrambles the contents using an algorithm and a key | Stop data being intercepted, copied or stolen — the data can still be taken |
| Makes the data meaningless or unusable to anyone without the key | Merely block access to a file — the contents themselves are scrambled |
| Lets the rightful owner decrypt it back with the correct key | Guarantee safety if the key itself is given away |
So encryption protects data by making it worthless to anyone without the key, rather than by hiding it or preventing it from being taken.
Practise this
OCR GCSE Computer Science · Utility software