Computer and Information Security Handbook, 3rd Edition

Chapter 8

Guarding Against Network Intrusions

Thomas M. Chen     City University London, Wales, United Kingdom

Abstract

The Internet exposes computer users to risks from a wide variety of possible threats, including direct intrusions by exploits or social engineering, malware, and web-based attacks. Perfect network security is generally believed to be infeasible. Instead, a defense-in-depth strategy is to hinder the attacker as much as possible with multiple layers of defense, even though each layer might be surmountable. The combination of multiple layers increases the cost for the attacker to be successful, and the cost is proportional to the value of the protected assets. The cost for the attacker could be in terms of additional time, effort, ...