Which term describes a centralized login mechanism allowing access to multiple systems using one credential?

Which term describes a centralized login mechanism allowing access to multiple systems using one credential?

• A. Single sign-on
• B. Password policy
• C. Federated identity
• D. Two-factor authentication

Answer: (A)

Single Sign-On is a centralized login mechanism that lets you authenticate once and then access multiple applications and services without re-entering credentials. The idea is to authenticate through a central identity provider, which issues a token or assertion that other systems trust, so you’re granted access to those apps seamlessly. This approach uses common protocols like SAML, OpenID Connect, or OAuth to share the identity securely across services, and it’s widely used to improve user convenience while giving security teams a single point to enforce policies and monitor access. Related ideas include federated identity, which describes how trust is established between different domains to enable cross-domain sign-on, but the mechanism described here is specifically the centralized login flow that enables access to many systems with one credential. The other options describe separate concepts: a password policy governs how passwords must be chosen and changed, two-factor authentication adds an extra verification step, and federated identity is about cross-domain trust rather than the act of signing in once for multiple systems.

Single Sign-On is a centralized login mechanism that lets you authenticate once and then access multiple applications and services without re-entering credentials. The idea is to authenticate through a central identity provider, which issues a token or assertion that other systems trust, so you’re granted access to those apps seamlessly. This approach uses common protocols like SAML, OpenID Connect, or OAuth to share the identity securely across services, and it’s widely used to improve user convenience while giving security teams a single point to enforce policies and monitor access. Related ideas include federated identity, which describes how trust is established between different domains to enable cross-domain sign-on, but the mechanism described here is specifically the centralized login flow that enables access to many systems with one credential. The other options describe separate concepts: a password policy governs how passwords must be chosen and changed, two-factor authentication adds an extra verification step, and federated identity is about cross-domain trust rather than the act of signing in once for multiple systems.