Web Links

Handbook of Applied Cryptography
www.cacr.math.uwaterloo.ca/hac/
The best reference book on cryptography. The whole book can be read online.

Sysinternals
http://www.sysinternals.com
Some must have utilities, many of them freeware, including RootkitRevealer, TCPView and NTRecover.

Foundstone
www.foundstone.com
Some useful security tools are available here including scanning tools and forensic tools.

Gibson Research Corporation
www.grc.com
Some usefull security utilities.

IT Tech Encyclopedia
http://www.techweb.com/encyclopedia
Provides an encyclopaedia of IT terms.

SecurityFocus
www.securityfocus.com
Portal site on IT Security, hosting the famous Bugtraq mailinglist, where vulnerabilities are posted as they are discovered.