Explanation should include

• secure design principles
• security mechanisms
• examples of how data can be protected when in the following states:
• Data at rest
• authentication (e.g., passwords, biometrics)
• encryption (symmetric and asymmetric)
• permissions
• backups
• perimeter security (e.g., firewall, Virtual Private Network [VPN])

• Data in transit
• cryptography
• Data being processed
• patching
• host hardening.