1. A condition that results from the establishment and maintenance of protective measures that ensure a state of inviolability from hostile acts or influences. 2. With respect to classified matter, the condition that prevents unauthorized persons from having access to official information that is safeguarded in the interests of national security. 3. Measures taken by a military unit, an activity or installation to protect itself against all acts designed to, or which may, impair its effectiveness. 4. The combination of confidentiality, integrity and availability. 5. The protection of computer hardware, software, and data from accidental or malicious access, use, modification, destruction, or disclosure. Tools for the maintenance of security are focused on availability, confidentiality, and integrity. 6. The combination of confidentiality, integrity, and availability.