Which authentication technology enables a user to authenticate once and receive authorizations for multiple services?

Which authentication technology enables a user to authenticate once and receive authorizations for multiple services?

• A. Multifactor Authentication (MFA)
• B. Single Sign-On (SSO)
• C. OAuth 2.0
• D. OpenID Connect

Answer: (B)

Single Sign-On lets you authenticate once with a central identity provider and then access multiple services without re-authenticating. After you log in, a session or token from the identity provider is trusted by each connected service, so you’re authorized to use them without signing in again. That direct one-login-for-many-services behavior is exactly what SSO provides, making it the best fit for this scenario. Multifactor Authentication adds extra verification steps for a single login, but it doesn’t by itself enable access to multiple services after one sign-in. OAuth 2.0 provides tokens to authorize apps to access resources, not a universal sign-on experience. OpenID Connect adds authentication on top of OAuth 2.0 and can enable SSO in many implementations, but the core capability described here—one login for multiple services—is the hallmark of Single Sign-On.

Single Sign-On lets you authenticate once with a central identity provider and then access multiple services without re-authenticating. After you log in, a session or token from the identity provider is trusted by each connected service, so you’re authorized to use them without signing in again. That direct one-login-for-many-services behavior is exactly what SSO provides, making it the best fit for this scenario.

Multifactor Authentication adds extra verification steps for a single login, but it doesn’t by itself enable access to multiple services after one sign-in. OAuth 2.0 provides tokens to authorize apps to access resources, not a universal sign-on experience. OpenID Connect adds authentication on top of OAuth 2.0 and can enable SSO in many implementations, but the core capability described here—one login for multiple services—is the hallmark of Single Sign-On.