Core

The CIA triad, security controls, threat actors and the core ideas every other topic builds on.

1. 01The CIA triad and beyondConfidentiality, integrity and availability: what they mean, how they trade off, and the extra properties exam answers often need.~4 min read
2. 02Threat actors and motivationsWho attacks systems, what they want, and why attribution and capability matter for defence.~3 min read
3. 03Security controls and defence in depthHow controls are categorised, why layers beat any single defence, and the principles that decide where controls go.~3 min read
4. 04Threat modellingSTRIDE, attack surfaces, attack trees and the kill chain: structured ways to work out what can go wrong before it does.~4 min read
5. 05Secure design principlesThe classic principles (economy of mechanism, open design, complete mediation and friends) that separate systems that age well from ones that don't.~4 min read