Which authentication factor uses physical traits for user identification?

Which authentication factor uses physical traits for user identification?

• A. Something you know
• B. Something you do
• C. Something you are
• D. Something you have

Answer: (C)

Physical traits used to identify a person fall under biometric authentication, the "Something you are" factor. Biometric methods rely on inherent biological characteristics—like fingerprints, iris patterns, facial features, or voice—making identification tied to the individual. This is different from secrets you know (passwords or PINs), actions you perform (typing speed or gait), or objects you possess (a token or phone). Biometric traits are unique to you and provide a direct way to verify identity based on who you are.

Physical traits used to identify a person fall under biometric authentication, the "Something you are" factor. Biometric methods rely on inherent biological characteristics—like fingerprints, iris patterns, facial features, or voice—making identification tied to the individual. This is different from secrets you know (passwords or PINs), actions you perform (typing speed or gait), or objects you possess (a token or phone). Biometric traits are unique to you and provide a direct way to verify identity based on who you are.