Which are the classic authentication factors?

Which are the classic authentication factors?

• A. Something you know
• B. Something you have
• C. Something you are
• D. All of the above

Answer: (D)

Authentication factors are the ways we prove someone’s identity. The classic ones are something you know (like a password or PIN), something you have (a token, smart card, or a mobile device for a code), and something you are (biometrics such as fingerprint or facial recognition). These form separate lines of defense, and using two or more of them—multi-factor authentication—greatly strengthens security because compromising one factor isn’t usually enough to gain access. Since the options include all three categories, the best answer is all of the above.

Authentication factors are the ways we prove someone’s identity. The classic ones are something you know (like a password or PIN), something you have (a token, smart card, or a mobile device for a code), and something you are (biometrics such as fingerprint or facial recognition). These form separate lines of defense, and using two or more of them—multi-factor authentication—greatly strengthens security because compromising one factor isn’t usually enough to gain access. Since the options include all three categories, the best answer is all of the above.