“If there was an Encyclopedia Britannica of computer security, it would be Hacking Exposed.”
--Marty Roesch, creator of the Snort tool

Other Hacking Exposed™ Editions

Hacking Exposed™ Linux, Second Edition
http://www.hackinglinuxexposed.com/

Hacking Exposed™ Windows Server 2003
http://www.winhackingexposed.com/

Hacking Exposed™ Computer Forensics
http://www.hackingexposedforensics.com/

Hacking Exposed™ Web Applications
http://www.webhackingexposed.com/

Hacking Exposed™ Cisco Networks
TBD

Here are links to the Forewords of Hacking Exposed.

Foreword to the First Edition, by Marcus Ranum
Creator of the first commercial firewall product and CEO of Network Flight Recorder, Inc.

Foreword to the Second Edition, by Bruce Schneier
CTO, Counterpane Internet Security, Inc.
http://www.counterpane.com

Foreword to the Third Edition, by Pete Murphy
SVP, Vulnerability and Response Management
Bank of America

Foreword to the Fourth Edition, by Patrick Heim, Vice President of Enterprise Security, McKesson Corporation

Foreword to the Fifth Edition, by Gene Hodges, President, McAfee Inc.

Foreword to Hacking Exposed Windows 2000, by Todd Sabin
Top security programmer and creator of the indispensable pwdump2 tool

Dictionaries
CERIAS Dictionary Archive

Encryption
RSA Lab's Cryptography FAQ
Bruce Schneier's paper on cryptography
Center for Democracy and Technology
Crypto and Security courses
Distributed.net
 

Famous Hacks
Internet Morris Worm '88
Kevin Mitnick's Site
Shimomura perspective of Mitnick hack
Code Red Worm
Slammer Worm
SCO Denial of Service Attack

Footprinting
ARIN database
Dogpile Search Engine
Filez database
InterNIC

Network Solutions (domain names)
Sam Spade
SEC database
WebSitez database

Gateway Services
Finger gateway
Ping gateway
Traceroute gateway
WHOIS gateways

General Security Sites
Active Matrix's Hideaway
Computer Security Information
Fyodor's Playhouse
Gene Spafford’s site
Hackers-supply
Internet Privacy Coalition
Macintosh Security
NT Security.net
Securityfocus.com

Government
Central Intelligence Agency
Defense Information Systems Agency (DISA)
Department of Energy
Federal Bureau of Investigation (FBI)
Lawrence Livermore National Labs
National Institute of Standards and Technology (NIST)
National Security Agency
President's Commission on Critical Infrastructure Protection

Hardening
NT Web security issues
SANS steps for hardening NT
Sendmail
Somarsoft's Windows NT security issues

Information Warfare
Institute for the Advanced Study of Information Warfare
Winn Schwartau's InfoWar

IRC Channels
#enforcers
#hackphreak
#x-treme
#coders
#nevaeh
#hackschool
#hackers
#dc-stuff

Legal Resources
Legal Information Institute
United States Code

Mailing Lists and Newsletters
AUSCERT
Bugtraq
CERT
COAST Watch
Firewall Wizards
IPSec
Microsoft
Netware Hack
NT Security
NTBugtraq
SANS Digest
Usenix ;login

News and Editorials
eWeek
SecurityFocus

Security Groups
Cult of the Dead Cow Nomad Mobile Research Center (NMRC)
The Legacy

Standards Bodies
IETF

Vendor Contacts
Apache Site
BSDI Patches Site
Cisco Advisory Site
Debian Site
Digital mail
FreeBSD Site
HP Site
IBM Site
Linux (in general)
Microsoft Site
NetBSD Site
Netscape Site
OpenBSD Site
RedHat Site
SCO Site
Sendmail Site
SGI Site
Slackware
Sun Site
WorkGroup Solutions Site

Vulnerabilities and Exploits
Security Focus
Shadow Penguin Security
System Security exploits
X-Force vulnerability database

Web and Application Security
Hacking Exposed – Web Applications
ActiveX - Conceptual Failure of Security
Designing Security Software by Peter Galvin
Java Security Hotlist Categories
Java Security: FAQ
Java versus ActiveX
Netscape's SSL 3.0 specification
Netscape's SSL Tech Briefs
Simson Garfinkel Tech article on the ActiveX threat
SSL FAQ
Sun's Applet Security: FAQ
W3C Security FAQ

War Dialing Tools and Sites
PhoneSweep by Sandstorm
M4phr1k