Federated Identity Management is a version of Single Sign-On where each device, system, and application queries a centralized database for authentication and authorization information.

In addition to the goals of any other identity management system, Federated Identity Management systems are tasked with enabling authentication and authorization data across organizational boundaries.

In a true Federated Identity Management system, authentication data can be passed across security domains from within a company to its business partners. This can enable Single Sign-On to extend past organizational boundaries.

Federated Identity Management is often abbreviated FIM.

Federated Identity Management Standards

The leader in developing standards for Federated Identity Management is The Liberty Alliance. The Liberty Alliance is a group of more than 150 corporations, non-profit organizations, and government entities which is tasked with developing open standards for Federated Identity Management.

Liberty Alliance Federated Identity Management Standards
ID-FF The Identity Federation Framework
ID-WSF The Identity Web Services Framework
ID-WSF DST The Data Services Template
ID-SIS A collection of Identity Services Interface Specifications

These standards are available online at the Liberty Alliance.