The internet is a worldwide collection of loosely connected networks that are accessible to anyone with a computer and a network connection. Thus, individuals and organizations can reach any point on the internet without regard to national or geographic boundaries or time of day.
Along with the convenience and easy access to information come risks. Among them are the risks that valuable information will be lost, stolen, changed, or misused. Intruders can steal or tamper with information without touching a piece of paper or a photocopier. They can also create new electronic files, run their own programs, and hide evidence of their unauthorized activity.
Three basic security concepts important to information on the internet are confidentiality, integrity, and availability. Concepts relating to the people who use that information are authentication, authorization, and nonrepudiation. This paper explains all of these concepts.