X.500 Security Feature

Security Feature

X.500 has evolved significantly, to encompass features not in the original X.500(1988) version. This has led to significant updates in the X.500 (1993) specification. Some smaller additions are also planned for X.500(1997). The major changes for X.500(1993) are: 

1. Sophisticated replication using Directory Information Shadowing Protocol (DISP). Replication of data is critical for providing a robust directory service. X.500 DISP provides this service, and gives a lot of flexibility for different replication configurations.
2. Access Control. There is a standard and flexible mechanism for specifying access control. This is important to allow open and controlled management of data in the directory, especially when the data is replicated.
3. Improvements to information model. There are a number of improvements to the X.500 data model, based on experience with X.500 (1988). These include attribute subtyping, which allows related attributes to be handled in a clean manner and operational attributes, which allow directory management attributes to be distinguished from user data.