# Single Sign-On (SSO)

**Unique, centralized authentication for a set of federated services.**

* The **identity of a client**, upon authentication, is **given to all federated services**.
* The identity attributes given to each service may vary.
* The **authenticator is called the Identity Provider (IdP)**.

Examples

* SSO authentication @ UA
  * Performed by a central IdP (idp.ua.pt).
  * The identity attributes are securely conveyed to the service accessed by the user.
