APPENDIX C

Principal Components of an Information Security Infrastructure

Component	Required Characteristics
Firewall	Provide single-point access from internal to external networks and vice versa; allow only authorized traffic as defined in security policy; authenticate outside users for internal services as defined in the security policy; provide application and cache proxy services (for complete details on Firewall characteristics, refer to Zwicky, Cooper, & Chapman, 2000)
Intrusion Detection System (IDS)	Support security policies of the organization; monitor intrusions on servers; provide priority-based alerts to system administrators; provide centralized management; implement automatic intrusion signature updates (for details on IDS, refer to Lodin, 1999)
Virus Protection System	Provide real-time virus protection for email and other Internet traffic; provide compatibility with deployed firewall products; provide flexible configuration and centralized management; implement automatic virus signature updates
Content Management System	Support content filtering as defined in the security policy; block spam mail messages; provide flexible configuration and centralized management; provide integration with firewall and virus protection systems