Linux Firewalls, Third Edition

How to Not Become Compromised

Virtually nothing can be done to stop an attacker with unlimited resources and unlimited time. From DoS attacks to rootkits to physical attacks, if someone wants at your data bad enough, chances are that he can get to it, given no other constraints. That said, there are many things you can do to limit your exposure to most risks.

Neither this chapter nor this book deals with physical attacks on any level. If an attacker is onsite and can simply walk off with the computer or hard drive containing the data, there's no amount of firewalling that will help. If the attacker has physical access to the computer or device holding the data, the attacker can steal the data itself or possibly plant his own malicious trojan ...