Kerberos

Overview

Kerberos is an authentication protocol developed by the Massachusetts Institute of Technology. Kerberos allows individuals communicating over an insecure network to prove their identity to one another in a secure manner. Kerberos authentication can be used to overcome weak points such as eavesdropping and replay attacks in other authentication mechanisms and to ensure the integrity of the data that is communicated.

The Kerberos authentication process involves several systems connected in a network, or a Kerberos realm. Kerberos authentication within a realm works on the basis of tickets, which serve to prove the authenticity of client requests. Kerberos authentication makes use of a trusted third party system called Key Distribution Center (KDC).

The KDC maintains a database of secret keys where each member system of a realm - whether a client or a server - shares a secret key known only to itself and to the Kerberos KDC. Knowledge of this key serves to prove the system's identity and this key never leaves the KDC. After the client is authenticated the KDC generates a session key for communication between the client and the application server, which they can use to secure their interactions.

Keywords Usages

Keyword	Elaboration
KDC	Key Distribution Center
TGT	Ticket Granting Ticket
TGS	Ticket Granting Server

References

• RFC 1510
• MIT's Kerberos
• NottingHack/hms
• Kerberos Hello World
• Administration programs
• How to Configure a Master KDC
• Integrated Kerberos-OpenLDAP provider
• Debian/Ubuntu Linux with AD Kerberos Server
• krb5-config missing debconf-set-selections variable
• How to Create, Use, and Store a New Master Key for the Kerberos Database