[ Thanks to Stanley for this link.
]
“The key to network security can be found in understanding the
choices and strategies available to you look to the building blocks
of network security. These include implementing user
authentication, using proxy servers and firewalls, setting up
demilitarized zones, and taking advantage of port- and
packet-filtering technologies. The overview of these security
solutions provided by this article will give you an understanding
of the technology. User authentication, the first option discussed
in this article, is the most basic component of network security,
and its success depends on the method used (encrypted, plain text,
and so forth), and on the ability to keep this information from
unauthorized personnel. Some of the more popular versions of user
authentication include the Password Authentication Protocol (PAP)
and the Challenge Handshake Authentication Protocol (CHAP)…”