Sponsor: ITU (International Telecommunications Union - Telecommunication Standardization Sector) and ISO (International Organization for Standardization)

Description: X.500 is an international standard for directory services.

Relationship to Records Management: At a minimum, White Pages directory services are necessary to identify authors, reviewers, contributors, editors, and other persons who may be associated with records. White Pages directory services are also useful for queries in which the name or attributes of the person may be known, while the titles or attributes of records with which they are associated may not be. To the degree that strong authentication such as digital signatures are required to authenticate E-records, directory services are essential to validate the signatures. Moreover, the original source documents by which the data in the directory was gathered, validated, and approved should be maintained as E-records for an appropriate period.

Problems/Issues/Weaknesses: X.500 was too resource-intensive (required too much computer and network capacity) to be implemented when it was first established. From a technical standpoint, that may no longer be the case. The complexity and level of detail specified in the standard are still perceived to be problems, but to some degree that may be a reflection of the natural competitive pressures for vendors to try to lock customers into their own proprietary products.

Closely Related Standards: LDAP and X.509

Links to More Information:

NetworkMagazine, August 1999, Special Report: Directories, by Elizabeth Clark, Special Report Editor http://networkmagazine.com/magazine/archive/1999/08/9908sr3intro.htm

Understanding X.500 - The Directory, Copyright 1994, 1996 D W Chadwick. http://www.salford.ac.uk/its024/Version.Web/Contents.htm

Understanding LDAP & X.500, by David Goodman, Lotus Development, and Colin Robbins, NEXOR http://www.eema.org/understanding_ldap.html

Understanding LDAP and X.500, European Electronic Messaging Association http://www.nexor.com/info/understandldap.htm

Report suggests GILS, X.500 link, by Colleen O'Hara, Federal Computer Week http://www.fcw.com/pubs/fcw/1118/policy.htm

Deploying X.500/LDAP Directories: Choices, Results and Functionalities Achieved and Not Achieved, by Jean-Pierre Gourdon, Ministry of External Affairs, in Messaging Magazine http://www.ema.org/html/pubs/mmv3n5/x500ldap.htm

X.500, An Introduction, by Alan Lloyd http://www.opendirectory.com/Whitepapers/x500tut.html

The Directory: Overview of Concepts, Models, and Services http://amazon.postech.ac.kr/~chkim1/x500_dir.html

X.500 Papers via NASA http://x500.ksc.nasa.gov/kmailpapers.html#x500rfc

X.500 Directory Service at NASA http://www.hq.nasa.gov/hq/x500.html

X.500 E-Mail Directory at NOAA http://directory.noaa.gov/systems.html

OpenDirectory White Papers http://www.opendirectory.com/frames4.htm

About the X.500 Directory (and data protection in the European Union) http://www.leeds.ac.uk/ucs/WWW/x500.html

Please convey corrections, updates, or suggested enhancements in this summary to: Owen_Ambur@fws.gov