The existence and enforcement of techniques which restrict access to data, and the conditions under which data may be obtained.

The ability of an electric power system to suitably respond to disturbances arising within that system, including both local and widespread disturbances and the loss of major generation and transmission facilities.

1. Measures taken by a command to protect itself from espionage, observation, sabotage, annoyance, or surprise.

2. A condition which results from the establishment and maintenance of protective measures which ensure a state of inviolability from hostile acts or influences.

3. Protection of supplies or supply establishments against enemy attack, fire, theft, and sabotage.