W3C Security Resources  
   Links to security initiatives such as PICS Signed Labels, and XML-DSig. (W3C)
   http://www.w3.org/Security/

Network Security, Filters and Firewalls  
   General introduction to network security issues and solutions in the Internet
   http://www.acm.org/crossroads/xrds2-1/security.html

Tiger Tools, Inc.  
   Tools for a professional security analysis.
   http://www.tigertools.net/

Common Vulnerabilities and Exposures  
   A searchable database of internet security problems.
   http://www.cve.mitre.org/

Dingbat's Warehouse  
   Information about viruses, intrusion detection software, personal firewalls, and privacy. Hosts a streaming webcast called The Byte Show on security-related topics; CD-ROMs of interviews and software available.
   http://www.thebyteshow.com/

Covert Channels in the TCP/IP Protocol Suite  
   Article on how to secretly transmit information using TCP headers.
   http://www.firstmonday.dk/issues/issue2_5/rowland/

Why the Internet is not secure.  
   An explanation of why consumer communications over the Internet are presently not secure.
   http://www.hydrophones.com/insecure.html

SuraSoft  
   Offers news, tutorials, articles, and forum.
   http://www.surasoft.com/

About.com Internet/Network Security  
   Featuring articles and web links on Internet and network security for the Unix and Windows platforms.
   http://netsecurity.about.com/index.htm

Dutch Security Information Network  
   Security news and links in English and Dutch.
   http://www.dsinet.org/

Operation Security  
   Directory of links and tools.
   http://www.operationsecurity.com/

Intelligent Hacker's Choice  
   Mailing list archives, technical articles, ask the expert, and news.
   http://www.netsys.com/

My online security  
   Security portal, providing internet security related news, resources, tools and services.
   http://www.myonlinesecurity.com

Baltimore Technologies  
   Public Key Infrastructure specialists offer security solutions, including certificate authorities, cryptographic toolkits for Java, C and XML; hardware cryptographic devices and security applications.
   http://www.baltimore.com/

NetWolves  
   Makes Internet gateway solutions for LAN-to-Internet connectivity. The FoxBox is an e-business platform for distance learning, data-security, VPN networks.
   http://www.netwolves.com/new_netwolves/index.php

Intrusion Detection FAQ  
   Frequently asked questions about intrusion detection, from the SANS Institute.
   http://www.sans.org/resources/idfaq/

Stay Safe Online  
   Tools and resources to empower home users, small businesses, schools and universities to stay safe online.
   http://www.staysafeonline.info/

wINJECT  
   Low-level packet builder/injector for win9x dialup users. It allows you to create custom packets with real or spoofed IP addresses.
   http://home19.inet.tele.dk/moofz/