A Short History of Cryptography
A brief historical analysis of the management of cryptography.
A Simple Scheme to Make Passwords Based on One-Way
Discusses the possibility that crackers might generate and distribute a massive list of encrypted passwords.
Firewall Piercing mini-HOWTO
Tutorial on using ppp over telnet to do network stuff transparently through an Internet firewall. (François-René Rideau)
Firewalling and Proxy Server HOWTO
Teaches the basics of firewall systems and give you some detail on setting up both a filtering and proxy firewall on a Linux based PC, by Mark Grennan.
Installing a firewall, Part 1
Get the details of a secure Trustix 1.1 installation
Introduction to Linux Networking and Security
Brief introduction to the IP networking services, how to configure them, and how to set up a relatively secure Linux workstation. Published in ACM Crossroads, the ACM student magazine.
Linux Administrator's Security Guide
A comprehensive security guide aimed at administrators and users, available online in Acrobat PDF format, by Kurt Seifried.
Linux Bridge+Firewall Mini-HOWTO
A tutorial on how to setup a bridge and a firewall with Linux, by Peter Breuer.
Linux Firewall Howto
Firewall HOWTO collection, ids, nids, hardening, penetration testing, auditing
Linux IPCHAINS-HOWTO
Describes how to obtain, install and configure the enhanced IP firewalling chains software for Linux, and how they might be used, by Paul Russell.
Linux Security HOWTO
Security issues that face the administrator, security philosophy, examples of how to secure the system from intruders.
Linux Security White Papers
A small collection of Linux security white papers and other information resources. The papers cover secure shell (ssh), host security, and firewalls.
Linuxs security basics
How to achieve the goal of every system admin: boring, predictable computers
Network Security Information: UNIX
Network Security Library has links to many UNIX (and, especially, Linux) security articles on host hardening, security admin guides, and special purpose hardening tips.
Ritter's Crypto Glossary and Dictionary of Te
Hyperlinked definitions and discussions of many cryptographic, mathematics, logic, statistics, and electronics terms used in cipher construction and analysis.
Rusty's Remarkably Unreliable Guides
Netfilter project provides HOWTOs for packet filtering, NAT and netfilter code hacking for Linux.
Secure POP via SSH mini-HOWTO
Explains how to set up secure POP connections using ssh, by Manish Singh.
Securing NIS
Provides a checklist on how to secure UNIX/Linux NIS (formerly YP) services in an intranet environment.
Security Overviews
Sec.ure.org contains overviews of security-enhancing procedures including Apache authentication, LDAP and several others.
Setting up a secure Linux server
Setting up a secure Linux server using RedHat and the Linux From Scratch system.
UnOfficial SELinux FAQ
A technical FAQ for the NSA SELinux project, which covers installation and implementation issues.
Using Term to Pierce an Internet Firewall
Tutorial on using 'term' to do network stuff through a TCP firewall that you're not supposed to be able to, by Barak Pearlmutter.
YoLinux: Internet Server Security HowTo and Tutori
This tutorial covers the installation and use of hacker protection software such as Portsentry, tripwire, ssh. It also covers configuration and administration steps to make a Linux server secure against hackers.