As a deployer, you manage a software application accessed daily by thousands of employees or millions of consumers. For every one of them you manage an account record, check credentials, control access to sensitive data or functions, and personalize the application's interface and behavior. For every one of them you go to a lot of trouble and expense to get identity, privacy, and security correct, not just because of the potential upside in user satisfaction and enterprise efficiency, but also because of the potential downside in business-threatening breaches.

Would you be interested in outsourcing a part of your identity management infrastructure—the authentication that begins user login sessions and even some user attribute data—to an external source? Conversely, would you be interested in exposing an interface to your user accounts for use by the applications that depend on that authentication and data? That's what federated identity is about: distributing identity information and tasks across security domains so that the parties involved can focus on the jobs they do best.

Read the complete article by Eve Maler.