Security

The protection of information and information systems against unauthorized accessor modification of information, whether in storage, processing, or transit, and againstdenial of service to authorized users. Information security includes those measuresnecessary to detect, document, and counter such threats. Information security iscomposed of computer security and communications security. Also calledINFOSEC. See also communications security; computer security; informationsecurity; information system.

http://www.thefreedictionary.com/It+security