Listed below is some of the writing I have done on matters of computer security, as well as security conference speaking engagements:

SecurityFocus

TCP/IP Skills Required of a Network Security Analyst Part I
TCP/IP Skills Required of a Network Security Analyst Part II
Packet Crafting for Firewall & IDS Audits Part I
Packet Crafting for Firewall & IDS Audits Part II
Software Firewalls: Made of Straw? Part I
Software Firewalls: Made of Straw? Part II
Windows NTFS Alternate Data Streams
Examining a Public Exploit Part I
Examining a Public Exploit Part II
The cost of security training
Practical Certifications
Packet forensics using TCP

Information Security Magazine

A Hacker's-Eye View

SCMagazine

In-House, within budget

O'Reilly ONLamp

Filtering IDS Packets
Detecting Network Intrusions with Packet Filtering

ISSA Journal

Aug 2004 Edition Feature article - The Dangers of Obfuscated Shellcode

Lockdown 2004

Packet Crafting for Firewall & IDS Audits

WindowSecurity

Darwinism meets the virus and the worm
Social Engineering meets the bot Part I
Social Engineering meets the bot Part II
Social Engineering meets the bot Part III
The Convergence of Hacking and Security Tools
Web Server Defacements Part I
Web Server Defacements Part II
Web Server Defacements Part III
How to Audit your Network via Packet Analysis
Obfuscated Shellcode, the Wolf in Sheep's Clothing (Part 1)
Obfuscated Shellcode, the Wolf in Sheep's Clothing (Part 2)
Obfuscated Shellcode, the Wolf in Sheep's Clothing (Part 3)
Sys Admin: Friend or Foe?
The Student, the Teacher, and Optix Pro (Part 1)
The Student, the Teacher, and Optix Pro (Part 2)
The Student, the Teacher, and Optix Pro (Part 3)
Packet Analysis tools and methodology (Part 1)
Packet Analysis tools and methodology (Part 2)
Packet Analysis tools and methodology (Part 3)
Packet Analysis tools and methodology (Part 4)
Standardization and the security appliance
Shells for Sale! (Part 1)
Shells for Sale! (Part 2)
Shells for Sale! (Part 3)