Status Updates From Security Engineering: A Gui...

‘security theatre’: when security is designed to produce a feeling
of security rather than the reality.

4 things to consider to build a dependable system:
- policy: what you're supposed to achieve
- mechanism: ciphers, or any machinery to implement policy
- assurance: amount of reliance for each mechanism & how well they work together
- incentive: the motive that the people guarding and maintaining
the system have to do their job properly, and also the motive that the attackers have to try to defeat your policy.

Software engineering is about ensuring
that certain things happen (“John can read this text”), while security is about ensuring that they don’t (“The Chinese government can’t read this text”)