Lessons · Cybersecurity · the three words: confidentiality, integrity, availability
The three words: secret, unchanged, available
Security protects three things: that data is seen only by the right people (confidentiality), that it is not changed without permission (integrity), and that it is there when needed (availability).
Hone is a place to practise a career, one idea a day. This is one of its lessons, written out in full and free to read without an account.
What it is for
A customer list emailed to the wrong address, a payroll figure quietly altered, a website that will not load on launch day: three very different mornings, and the first question in each is which of the three words was broken.
How to think about it
When something goes wrong, ask which word it hurt. Seen by the wrong person is confidentiality. Changed without permission is integrity. Not there when needed is availability. The word tells you which controls to reach for.
Worked example
Scene: a spreadsheet of salaries sent to the whole companyNothing was changed and nothing went offline. The wrong people saw it: confidentiality.
Scene: an invoice's bank account number edited before paymentEverybody who should see it can. The data is wrong: integrity.
Scene: the booking site down for six hours on a SaturdayNothing leaked and nothing was altered. It was not there: availability.
Write the word first, then the controlConfidentiality points at access control and encryption; integrity at hashing and change control; availability at backups and redundancy.
Your turn
The online shop is unreachable for three hours because its one server crashed. Write the word that was broken.
broken:
Solve one, graded on the server
The trap
Calling everything confidentiality. Half of security is about data being right and being there, and a backup plan is a security control as much as a password is.