Which statement defines Authentication?

• A. A path used to gain unauthorized access to a system.
• B. Granting permissions after authentication.
• C. Ensuring data is not altered.
• D. Verifying the identity of a user or system.

Answer: (D)

Authentication is the process of verifying the identity of a user or system. When you log in with a password, scan a fingerprint, or use a security token, the system checks that you are who you claim to be before granting access. This step happens before deciding what you are allowed to do, which is handled by authorization. The other ideas touch on related concepts but aren’t about proving identity: a path to gain unauthorized access describes an attack or vulnerability, and ensuring data isn’t altered refers to data integrity. Granting permissions after authentication describes authorization, not authentication.