Security: It is a degree of protection of computer hardware and software from intentional or unintentional changes, uses, spoofing, spread of information over unauthorized people.

• Reliability: It describes the ability of a system to maintain its function under a given set of conditions for a certain period of time.

• Adversary: Any person, group or force that may intentionally infringe on the integrity, confidentiality and availability of information.

• Security rules: Necessary regulations to keep the computer secure from malicious attacks.

• Security breach: It is a software or hardware failure or incompleteness which could result in accessing the computer security.