Enterprise Identity Mapping (EIM) for iSeries™ is the i5/OS™ implementation of an IBM® 
infrastructure that allows administrators and
application developers to solve the problem of managing multiple user registries
across their enterprise. Most network enterprises face the problem of multiple
user registries, which require each person or entity within the enterprise
to have a user identity in each registry. The need for multiple user registries
quickly grows into a large administrative problem that affects users, administrators,
and application developers. Enterprise Identity Mapping (EIM) enables inexpensive
solutions for easier management of multiple user registries and user identities
in your enterprise.
EIM allows you to create a system of identity mappings, called associations, between the various user identities in various user registries for a person in your enterprise. EIM also provides a common set of APIs that can be used across platforms to develop applications that can use the identity mappings that you create to look up the relationships between user identities. In addition, you can use EIM in conjunction with network authentication service, the i5/OS implementation of Kerberos, to provide a single signon environment.
You can configure and manage EIM through iSeries Navigator, the iSeries graphical user interface. The iSeries server uses EIM to enable i5/OS interfaces to authenticate users by means of network authentication service. Applications, as well as i5/OS, can accept Kerberos tickets and use EIM to find the user profile that represents the same person as the Kerberos ticket represents.
To learn more about how EIM works, about EIM concepts, and about how you can use EIM in your enterprise review the following: