Which concept enables users to access resources across multiple identity providers using a common authentication mechanism?

Which concept enables users to access resources across multiple identity providers using a common authentication mechanism?

• A. Single sign-on
• B. Multifactor authentication
• C. Password synchronization
• D. Federation

Answer: (D)

Federation is the mechanism that lets different organizations’ identity providers trust each other so a user can sign in with their home identity and access resources across other domains. It uses standards like SAML, OpenID Connect, and OAuth to exchange authentication assertions and user attributes, creating a seamless cross‑domain login experience. In this model, the actual authentication is handled by the user’s home provider, but other service providers accept the resulting token or assertion, enabling access across multiple identity providers with a single, common authentication framework. The other options address related security or credential management aspects—single sign-on focuses on avoiding repeated logins within a trust boundary, multifactor authentication adds factors for security, and password synchronization simply keeps credentials aligned but doesn’t establish cross‑domain trust.

Federation is the mechanism that lets different organizations’ identity providers trust each other so a user can sign in with their home identity and access resources across other domains. It uses standards like SAML, OpenID Connect, and OAuth to exchange authentication assertions and user attributes, creating a seamless cross‑domain login experience. In this model, the actual authentication is handled by the user’s home provider, but other service providers accept the resulting token or assertion, enabling access across multiple identity providers with a single, common authentication framework. The other options address related security or credential management aspects—single sign-on focuses on avoiding repeated logins within a trust boundary, multifactor authentication adds factors for security, and password synchronization simply keeps credentials aligned but doesn’t establish cross‑domain trust.