1.\" $Id: kerberos.8,v 1.2 2001/05/02 08:59:23 assar Exp $ 2.\" 3.Dd September 1, 2000 4.Dt KERBEROS 8 5.Os HEIMDAL 6.Sh NAME 7.Nm kerberos 8.Nd introduction to the Kerberos system 9.Sh DESCRIPTION 10Kerberos is a network authentication system. It's purpose is to 11securely authenticate users and services in an insecure network 12environment. 13.Pp 14This is done with a Kerberos server acting as a trusted third party, 15keeping a database with secret keys for all users and services 16(collectively called 17.Em principals ) . 18.Pp 19Each principal belongs to exactly one 20.Em realm , 21which is the administrative domain in Kerberos. A realm usually 22corresponds to an organisation, and the realm should normally be 23derived from that organisation's domain name. A realm is served by one 24or more Kerberos servers. 25.Pp 26The authentication process involves exchange of 27.Sq tickets 28and 29.Sq authenticators 30which together prove the principal's identity. 31.Pp 32When you login to the Kerberos system, either through the normal 33system login or with the 34.Xr kinit 1 35program, you acquire a 36.Em ticket granting ticket 37which allows you to get new tickets for other services, such as 38.Ic telnet 39or 40.Ic ftp , 41without giving your password. 42.Pp 43For more information on how Kerberos works, and other general Kerberos 44questions see the Kerberos FAQ at 45.Pa http://www.nrl.navy.mil/CCS/people/kenh/kerberos-faq.html . 46.Pp 47For setup instructions see the Heimdal Texinfo manual. 48.Sh SEE ALSO 49.Xr ftp 1 50.Xr kdestroy 1 , 51.Xr kinit 1 , 52.Xr klist 1 , 53.Xr kpasswd 1 , 54.Xr telnet 1 55.Sh HISTORY 56The Kerberos authentication system was developed in the late 1980's as 57part of the Athena Project at the Massachusetts Institute of 58Technology. Versions one through three never reached outside MIT, but 59version 4 was (and still is) quite popular, especially in the academic 60community, but is also used in commercial products like the AFS 61filesystem. 62.Pp 63The problems with version 4 are that it has many limitations, the code 64was not too well written (since it had been developed over a long 65time), and it has a number of known security problems. To resolve many 66of these issues work on version five started, and resulted in IETF 67RFC1510 in 1993. Since then much work has been put into the further 68development, and a new RFC will hopefully appear soon. 69.Pp 70This manual manual page is part of the 71.Nm Heimdal 72Kerberos 5 distribution, which has been in development at the Royal 73Institute of Technology in Stockholm, Sweden, since about 1997. 74