Which security control enables users to authenticate once to access multiple SaaS applications?

Which security control enables users to authenticate once to access multiple SaaS applications?

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

Answer: (A)

Single sign-on lets a user authenticate once with a centralized identity provider and then access multiple SaaS applications without re-entering credentials. After the initial login, the identity provider issues a token or assertion that each SaaS app trusts, enabling seamless access across those apps in the same session. This reduces password prompts and lets security policies be applied centrally, using standard protocols like SAML, OAuth, or OpenID Connect. Multifactor authentication adds extra verification steps but doesn’t by itself enable access to multiple apps after one login. Password synchronization keeps the same password across systems but doesn’t provide seamless access to multiple services. Federation describes the trust relationship that makes SSO possible across domains, but the actual capability to sign in once for multiple apps comes from the single sign-on process.

Single sign-on lets a user authenticate once with a centralized identity provider and then access multiple SaaS applications without re-entering credentials. After the initial login, the identity provider issues a token or assertion that each SaaS app trusts, enabling seamless access across those apps in the same session. This reduces password prompts and lets security policies be applied centrally, using standard protocols like SAML, OAuth, or OpenID Connect.

Multifactor authentication adds extra verification steps but doesn’t by itself enable access to multiple apps after one login. Password synchronization keeps the same password across systems but doesn’t provide seamless access to multiple services. Federation describes the trust relationship that makes SSO possible across domains, but the actual capability to sign in once for multiple apps comes from the single sign-on process.