Classes of intruders.

List and briefly define three classes of intruders.
What are two common techniques used to protect a password file?
What are three benefits that can be provided by an intrusion detection system?
What is the difference between statistical anomaly detection and rule-based intrusion detection?
What metrics are useful for profile-based intrusion detection?
What is the difference between rule-based anomaly detection and rule-based penetration identification?
What is a honeypot?
What is a salt in the context of UNIX password management?
List and briefly define four techniques used to avoid guessable passwords.