For the scenarios/examples 1 through 4, identify the most appropriate security design principle that applies to it and also explain your choice of principle that applies to the example with reasons.

1. A retail store keeps its back door closed and locked to prevent thefts. An outsider can't enter a store via an emergency exit, and insiders may use it only in emergencies. "panic lock" allows the door to open during an emergency.

2. A system operator should not perform security administration functions

3. An authentication mechanism that requires both biometric and token recognition systems.

4. Viruses cause havoc because, any program or script that is downloaded or received as email attachment, runs with the privileges of the user that runs them. Or worse the privileges of the application.