Algorithm: A recipe for doing something on a computer. Algorithms may be logical, or mathematical; for example, “If the temperature exceeds 73 degrees, turn on the air conditioner” or “Add two numbers together and print the results.” Algorithms power every decision a computer makes.
Auditing: Just like financial auditing, IT auditing looks for indications of misbehavior. IT security audits look specifically for evidence of break-ins by an attacker. Together with Authentication and Authorization, these make up the AAA of information assurance.
Authentication: An entity proving that they are who they claim to be. Together with Authorization and Auditing, these make up the AAA of information assurance.
Authorization: The permissions granted ...