The CIA Triad

A security model similar to and building up on CIA has not three but five principles.

It is named The Five Pillars Of Information Assurance, and it was proposed by the U.S. Department of Defense.

The five principles are listed below and are defined as follows:

1. Confidentiality is defined the same way as on slide 20.
2. Integrity is defined in a similar way to the one on slide 22, except that Integrity here doesn't assume the confirmation of a person's identity.
3. Availability is defined the same way as on slide 24.
4. Authenticity is the ability to confirm a person's (such as a computer user's or a message sender's) identity.
5. Non-Repudiation is the ability to obtain proof of a message's delivery in a way that prevents the sender from denying that he or she sent or wrote the message (repudiation = denial of one's actions.)