Digital Equipment Corporation
The Kerberos Network Authentication Service (V5)
Status of this Memo
This RFC specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" for the standardization state and status
of this protocol. Distribution of this memo is unlimited.
This document gives an overview and specification of Version 5 of the
protocol for the Kerberos network authentication system. Version 4,
described elsewhere [1,2], is presently in production use at MIT's
Project Athena, and at other Internet sites.
Project Athena, Athena, Athena MUSE, Discuss, Hesiod, Kerberos,
Moira, and Zephyr are trademarks of the Massachusetts Institute of
Technology (MIT). No commercial use of these trademarks may be made
without prior written permission of MIT.
This RFC describes the concepts and model upon which the Kerberos
network authentication system is based. It also specifies Version 5
of the Kerberos protocol.
The motivations, goals, assumptions, and rationale behind most design
decisions are treated cursorily; for Version 4 they are fully
described in the Kerberos portion of the Athena Technical Plan .
The protocols are under review, and are not being submitted for
consideration as an Internet standard at this time. Comments are
encouraged. Requests for addition to an electronic mailing list for
discussion of Kerberos, kerberos@MIT.EDU, may be addressed to
kerberos-request@MIT.EDU. This mailing list is gatewayed onto the
Usenet as the group comp.protocols.kerberos. Requests for further
information, including documents and code availability, may be sent
The Kerberos model is based in part on Needham and Schroeder's
trusted third-party authentication protocol  and on modifications
suggested by Denning and Sacco . The original design and
implementation of Kerberos Versions 1 through 4 was the work of two
former Project Athena staff members, Steve Miller of Digital
Equipment Corporation and Clifford Neuman (now at the Information
Sciences Institute of the University of Southern California), along
with Jerome Saltzer, Technical Director of Project Athena, and
Jeffrey Schiller, MIT Campus Network Manager. Many other members of
Project Athena have also contributed to the work on Kerberos.
Version 4 is publicly available, and has seen wide use across the
Version 5 (described in this document) has evolved from Version 4
based on new requirements and desires for features not available in
Version 4. Details on the differences between Kerberos Versions 4
and 5 can be found in .