What security actually means

Before any tools, the ideas the whole field is built on, the same ones every certificate opens with. Across five short topics you will learn what security protects, how to weigh a risk, the kinds of defence, how to limit damage when something gets in, and how to think like both an attacker and a defender. Each idea is taught through a real breach you will recognise.

1. 1
   The CIA triad: what security is protectingStart

   The three-word idea at the heart of all cyber security, and a real attack that took one of the three away.

   ~18 min3 ideas1 real case1 lab
2. 2
   Threat, vulnerability, and riskUp next

   Pin down three words people mix up, then see the breach one unpatched weakness caused.

   ~18 min3 ideas1 real case1 lab
3. 3
   The kinds of defence: preventive, detective, correctiveUp next

   The three jobs a security control can do, and the breach where the alarm was ignored.

   ~18 min3 ideas1 real case1 lab
4. 4
   Defence in depth and least privilegeUp next

   The two ideas that limit the damage once an attacker is in, and the attack that ignored them.

   ~18 min3 ideas1 real case1 lab
5. 5
   Thinking like a defender, and an attackerUp next

   The two mindsets security runs on, and the attack that broke the deepest assumption of all.

   ~18 min3 ideas1 real case1 lab