Security in Computing, Third Edition

7.4. Firewalls

Firewalls were officially invented in the early 1990s, but the concept really reflects the reference monitor (described in Chapter 5) from two decades earlier. The first reference to a firewall by that name may be [RAN92]; other early references to firewalls are the Trusted Information Systems firewall toolkit [RAN94] and the book by Cheswick and Bellovin [CHE94, updated as CHE02].

What Is a Firewall?

A firewall is a device that filters all traffic between a protected or “inside” network and a less trustworthy or “outside” network. Usually a firewall runs on a dedicated device; because it is a single point through which traffic is channeled, performance is important, which means nonfirewall functions should not be done on the same ...