- Confidentiality – Is a term in which to ensure that the data should be only read (readable) to/by the authorised people. For example, Cryptography and Encryption methods are an example of an attempt to ensure confidentiality of data transferred from one computer to another.
- Integrity – This term is given to the data that must not be changed in transit; and the taken steps must be implemented to ensure that data cannot be altered by unauthorised people. In another word, it is the ability to ensure that the data are accurate and unchanged representation of the original secure information.
- Availability – Is the fact that ensures the system components (Hardware and Software) are available and authorised to people when they need it (at all time). For example, a particular search engine is trying to ensure that their web/services are available (Still running).
- Accountability – Is the traceability of actions performed on a system, in order to prove if a person did something wrong (with knowing the who did that).
- Non-repudiation – Is the fact of proving something without denying it. For example, if a person misses with the system, that person cannot deny it.
- Accessibility – Is the fact that ensures the system components (Hardware and Software) are accessible and available to certain people when they need it. For example, the same search engine’s admin should ensure that the web/services are available (Still running) and accessible to authorised people.
- Authentication – Is the fact of proving who you say you are (or who he/she claims to be).
- Authorisation – Refers to the rules that determine who is allowed to do what. For example, Mike (Admin) may be authorised to create and delete databases, while Tom (User) is only authorised to read.
Note: In computer security CIA does not refer to Central Intelligence Agency, but it does refer to Confidentiality, Integrity, Availability or Authentication. Some people say the letter “A” refers to the big “A”, which means that it concludes everything that starts with the letter “A” such as, Accountability, Authorisation, Authentication, Accessibility and more.