KERBEROS(8) UNIX System Manager's Manual KERBEROS(8) NNAAMMEE kkeerrbbeerrooss - introduction to the Kerberos system DDEESSCCRRIIPPTTIIOONN 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 (collec- tively called _p_r_i_n_c_i_p_a_l_s). Each principal belongs to exactly one _r_e_a_l_m, 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 _t_i_c_k_e_t _g_r_a_n_t_i_n_g _t_i_c_k_e_t which allows you to get new tickets for other services, such as tteellnneett or ffttpp, without giving your password. For more information on how Kerberos works, and other general Kerberos questions see the Kerberos FAQ at _h_t_t_p_:_/_/_w_w_w_._n_r_l_._n_a_v_y_._m_i_l_/_C_C_S_/_p_e_o_p_l_e_/_k_e_n_h_/_k_e_r_b_e_r_o_s_-_f_a_q_._h_t_m_l. For setup instructions see the Heimdal Texinfo manual. SSEEEE AALLSSOO ftp(1), kdestroy(1), kinit(1), klist(1), kpasswd(1), telnet(1) HHIISSTTOORRYY 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 RFC1510 in 1993. Since then much work has been put into the further development, and a new RFC will hopefully appear soon. This manual manual page is part of the HHeeiimmddaall Kerberos 5 distribution, which has been in development at the Royal Institute of Technology in Stockholm, Sweden, since about 1997. HEIMDAL September 1, 2000 1