The Internet is a very insecure place. Many of the current protocols don't provide adequate security, leaving web applications that send unencrypted passwords over the network vulnerable to malicious hackers using password "sniffing" tools. To combat these deficiencies, researchers at MIT created an authentication protocol called Kerberos. Kerberos: The Definitive Guide provides a thorough introduction to Kerberos terminology and explores all the details of the protocol. Everything is here, from implementation to troubleshooting, including ways to add Kerberos to software packages.