krb5-kdc 1.8.1+dfsg-2ubuntu0.13 (amd64 binary) in ubuntu lucid

 Kerberos is a system for authenticating users and services on a network.
 Kerberos is a trusted third-party service. That means that there is a
 third party (the Kerberos server) that is trusted by all the entities on
 the network (users and services, usually called "principals").
 .
 This is the MIT reference implementation of Kerberos V5.
 .
 This package contains the Kerberos key server (KDC). The KDC manages all
 authentication credentials for a Kerberos realm, holds the master keys
 for the realm, and responds to authentication requests. This package
 should be installed on both master and slave KDCs.