Interesting Security related WEB sites
Trade Publication Sites
ZDNet: eWEEK: Security Homepage
InfoWorld - Security Watch Column
Information Security Magazine
Crypto-Gram Newsletter
ComputerWorld Security Site
Windows Magazine Security
Earth WEB

Organizations
Security Focus
SANS Home Page
International Computer Security Association
Computer Emergency Response Team Coordination Center
Center for Education and Research in Information Assurance and Security
Computer and Network Security Reference List 
Center for Democracy and Technology
Center for Internet Security
National Infrastructure Protection Center
Information Technology Assoication of Amercia - Info Sec

Companies with Security Products
PGP products and servicesNetwork Security Essentials: Applications and Standards
Symantec Enterprise Security
Verisign: A leading commercial vendor of X.09-related products; white papers and other worthwhile material at this site.
Counter Pane - Bruce Scheier's company
 

Hacking Related Sites
Hacking Exposed
2600 
HNN - Hacker News Network
AntiOnline - Computer Security - Hacking and Hackers
Phrack
l0pht
The Happy Hacker
The Hackers Club

Overview

Security Research and Academic Sites
COAST: Comprehensive set of links to sites related to cryptography and network security. 
Computer Security Laboratory - UC Davis

IETF Security Area: Keep up to date on Internet security standardization efforts
USENIX Symposium on Security Proceedings
 

Meta Pages
Tom Dunigan's Security Page: An excellent list of pointers to cryptography and network security web sites.

IEEE Technical Committee on Security and Privacy: An excellent list of pointers to cryptography and network security web sites.

Conventional Encryption and Message Confidentiality
AES Home Page: NIST's page on the forthcoming Advanced Encryption Standard.

Authentication Applications
MIT Kerberos Site: Information about Kerberos, including the FAQ, papers and documents, and pointers to commercial product sites.
USC/ISI Kerberos Page: Another good source of Kerberos material.
Public-Key Infrastructure Working Group: IETF group developing standards based on X.509v3.

Tutorials and Education
ZD-How-To Privacy and Security
Securing your Intranet
PKI Tutorial
 

Electronic Mail Security
PGP Home Page: PGP Web site by Network Associates
MIT Freeware PGP
S/MIME Charter: Latest RFCs and internet drafts for S/MIME.
S/MIME Central: RSA Inc.'s Web site for S/MIME. Includes FAQ and other useful information.
 

IP Security
IPSEC Charter: Latest RFCs and internet drafts for IPsec.
IPSEC Working Group News: Working group documents, mail archives, related technical papers, and other useful material.
IPSEC Resources: List of companies implementing IPSec, implementation survey, and other useful material.
 

Web Security
Netscape's SSL Page: Contains the SSL specification.
TLS Charter: Latest RFCs and internet drafts for TLS.
MasterCard SET Site: Latest SET documents, glossary of terms, and application information.
Visa Electronic Commerce Site: Similar information to that at the MasterCard Site.
SETCo LLC: Organization that promotes SET.
 

Network Management Security
IETF SNMPv3 Working Group: Maintains the most recent copies of SNMPv3-related RFCs and internet draft documents, plus a schedule of past and future work.
SNMPv3 Web Site: Maintained by the Technical University of Braunschweig. It provides links to the RFCs and internet drafts, copies of clarifications and proposed changes posted by the working group, and links to vendors with SNMPv3 implementations.
The Simple Web Site: Maintained by the University of Twente. It is a good source of information on SNMP, including pointers to many public-domain implementations and lists of books and articles.
 

Intruders and Viruses
CERT Coordination Center: The organization that grew from the computer emergency response team formed by the Defense Advanced Research Projects Agency. Site provides good information on Internet security threats, vulnerabilities, and attack statistics.
Anti-Virus On Line: IBM's site on virus information; one of the best.

Biometric Authentication
Fingerprint readers - Identix Biologon

Shareware/Freeware Software

Virus Information