The Cyber Security Triad - It’s the CIA 🕵 — but maybe not what you think

The Cyber Security Triad, also called the CIA triad, is a set of three goals:

Confidentiality: Information or resources can only be accessed by authorized parties.
Integrity: Information can only be added, edited, or removed by authorized parties.
Availability: Systems are available to their users according to the service level agreements (SLAs).

A triangle with Confidentiality at the apex and Integrity and Availability at the base corners — The three goals of the CIA triad. Image by Martin Thoma

Email Example

Confidentiality: Ideally, only the sender and the receiver can read an email. (Without end-to-end encryption, the mail providers can read it as well.)
Integrity: Only you can delete emails you received. Nobody can edit the emails you received.
Availability: You can read emails in your inbox whenever you want.

WhatsApp Example

Let’s ignore groups for the moment.

Confidentiality: Only the sender and the receiver can read a message.
Integrity: Only you can delete messages you received, with the exception of messages you haven’t read / which are not older than a certain time. Nobody can edit the messages you received.
Availability: You can read your messages whenever you want.

Please note that the integrity criterion is different for WhatsApp compared to email! This shows that the meaning of the criterion depends on the context. Similarly, availability in many business applications can mean “available at typical business hours”.