Protecting data and systems

Every threat to data, from theft to viruses, has a countermeasure that reduces the harm. Some are physical, like locks and backups; some are software, like passwords and antivirus. Paper 1 asks what scrambling a message before sending and unscrambling it on arrival is called: **encryption**.

By the end of this page you can

• Tell physical and software countermeasures apart
• Explain encryption and firewalls
• Describe safe personal practices online
• Match a countermeasure to a threat

Goals tick themselves off as you try the activities below.

Photo: Santeri Viinamäki, CC BY-SA 4.0, via Wikimedia Commons. Cropped, padlock maker’s mark blurred, resized, JPEG q72.

Physical security protects the machine; software security protects the data inside.