The CIA Triad
At 12:30 the Tiffin ordering page is down, a customer says their address showed up on someone else's receipt, and the kitchen swears a price changed on its own. Three problems, three different fixes. Before you can protect anything, you need words for what went wrong. Security uses three.
The rule
Keep it secret, keep it correct, keep it available.
- Confidentiality: only the right people can see the data. A leaked address breaks it. Encryption and access control protect it.
- Integrity: data and code are correct and unaltered, unless changed by someone allowed to. A tampered price breaks it. Checksums, signatures and change controls protect it.
- Availability: the system works when it is needed. The lunchtime outage breaks it. Redundancy, backups and rate limiting protect it.
The same three words work for any asset, not just customer data. Source code, pipeline secrets and container images all have a confidentiality, an integrity and an availability side, and an attacker usually targets whichever one is weakest.
The three pull against each other. Locking everything away helps confidentiality and hurts availability; a system nobody can reach is perfectly secret and perfectly useless. Good design balances them for what the data is worth.
The triad applies to the pipeline too, not just the app:
package:
steps:
- run: build-image tiffin:1.4.2
- run: sign-image tiffin:1.4.2 # integrity: prove this is the tested build
deploy:
steps:
- run: verify-signature tiffin:1.4.2The shortcut
For any incident or control, ask one question: was it seen, changed, or stopped?
- Seen by the wrong person → confidentiality.
- Changed without permission → integrity.
- Stopped from working → availability.
The address on the wrong receipt
Someone saw data they should not. Confidentiality.
The common mistake is to call every problem "a data leak". Ransomware that encrypts your database leaks nothing, yet it breaks availability, and possibly integrity. Name the property first; the right control follows.
Drills
Answer fast — trust the rule.
An API key for Tiffin's payment provider is pasted into a public chat. Which property is broken?
Signing a container image after tests and verifying the signature before deployment mainly protects…
A database backup restored after a disk failure mainly protects which property?
Ransomware encrypts Tiffin's order database so nobody can use it. Which property is hit most directly?
Remember
- Confidentiality, integrity, availability: secret, correct, reachable.
- Ask "was it seen, changed, or stopped?" to name the property.
- The three trade off; protect each in proportion to what the data is worth.