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KERBEROS(8)                 System Manager's Manual                KERBEROS(8)

     kerberos - introduction to the Kerberos system

     Kerberos is a network authentication system. Its purpose is to securely
     authenticate users and services in an insecure network environment.

     This is done with a Kerberos server acting as a trusted third party,
     keeping a database with secret keys for all users and services
     (collectively called principals).

     Each principal belongs to exactly one realm, which is the administrative
     domain in Kerberos. A realm usually corresponds to an organisation, and
     the realm should normally be derived from that organisation's domain
     name. A realm is served by one or more Kerberos servers.

     The authentication process involves exchange of `tickets' and
     `authenticators' which together prove the principal's identity.

     When you login to the Kerberos system, either through the normal system
     login or with the kinit(1) program, you acquire a ticket granting ticket
     which allows you to get new tickets for other services, such as telnet or
     ftp, without giving your password.

     For more information on how Kerberos works, and other general Kerberos
     questions see the Kerberos FAQ at

     For setup instructions see the Heimdal Texinfo manual.

     ftp(1), kdestroy(1), kinit(1), klist(1), kpasswd(1), telnet(1), krb5(3),
     krb5.conf(5), kadmin(1), kdc(8), ktutil(1)

     The Kerberos authentication system was developed in the late 1980's as
     part of the Athena Project at the Massachusetts Institute of Technology.
     Versions one through three never reached outside MIT, but version 4 was
     (and still is) quite popular, especially in the academic community, but
     is also used in commercial products like the AFS filesystem.

     The problems with version 4 are that it has many limitations, the code
     was not too well written (since it had been developed over a long time),
     and it has a number of known security problems. To resolve many of these
     issues work on version five started, and resulted in IETF RFC 1510 in
     1993. IETF RFC 1510 was obsoleted in 2005 with IETF RFC 4120, also known
     as Kerberos clarifications. With the arrival of IETF RFC 4120, the work
     on adding extensibility and internationalization have started (Kerberos
     extensions), and a new RFC will hopefully appear soon.

     This manual page is part of the Heimdal Kerberos 5 distribution, which
     has been in development at the Royal Institute of Technology in
     Stockholm, Sweden, since about 1997.

NetBSD 10.99                     Jun 27, 2013                     NetBSD 10.99