Computer security has three main elements that can easily be remembered using the acronym CIA: Confidentiality, Integrity, Availability.

• Confidentiality is the task of ensuring that only those entities (persons or systems) cleared for access can read information. Cryptography is a key element in ensuring confidentiality.
• Integrity is the task of ensuring that information is correct, and stays that way.
• Availability is the task of ensuring that systems responsible for delivering, storing and processing information are accessible when needed, by those who need them. This includes, for example, protection against denial of service (DoS) attacks.

See also

• UNIX Computing Security