The CIA Triad — Confidentiality, Integrity, Availability
Why does every computer user need to think about security?
- Define computer security
- Explain each pillar of the CIA triad
- Give one school-life example for Confidentiality, Integrity and Availability
Overview
Computer security is the practice of protecting digital information and the systems that store it. Every phone, laptop, and school server holds assets — things of value such as personal photos, exam marks, or bank details. Attackers want to steal, change, or block access to those assets, so we need a way to think clearly about what we are defending. The CIA triad gives us three simple pillars: Confidentiality, Integrity, and Availability. Any real-world security decision — from setting a password to backing up files — supports at least one of them.
Confidentiality
Confidentiality means keeping information secret from people who should not see it. Your password, your medical record, and your family's WhatsApp chats are all confidential. We protect confidentiality with passwords, encryption, and access rules.
Integrity
Integrity means information stays accurate and complete. If a classmate secretly changes your exam mark in the school system, integrity is broken — even if nothing was stolen. We protect integrity with checksums, digital signatures, and permissions that stop unauthorised edits.
Availability
Availability means the system is ready when you need it. If online banking crashes at month-end, the money is safe but availability has failed. We protect availability with backups, reliable power, and defences against denial-of-service attacks.
Classify the Scenario
- In pairs, read each of the six scenarios below.
- Decide which pillar (C, I or A) is most affected.
- Scenarios: (1) A student peeks at another's password; (2) A hacker edits exam marks; (3) The school website is offline during registration; (4) An email attachment leaks staff salaries; (5) A virus deletes half your homework; (6) The Wi-Fi router is switched off during a test.
- Define computer security in one sentence.
Reveal answer
Protecting information and systems from unauthorised access, change or disruption.
- Which pillar is broken when someone changes a grade in the database?
Reveal answer
Integrity.
- Give one school example of an availability failure.
Reveal answer
The school portal is down during online enrolment.
- Why is confidentiality alone not enough?
Reveal answer
Data can still be corrupted or made unavailable even if it is kept secret.
List 5 personal digital assets at home and tag each with C, I or A.