What Is Two-Factor Authentication (2FA)? - Authy
https://authy.com/what-is-2faOther Forms of Two-Factor Authentication. Biometric 2FA, authentication that treats the user as the token, is just around the corner. Recent innovations include verifying a person’s identity via fingerprints, retina patterns, and facial recognition. Ambient noise, pulse, typing patterns, and vocal prints are also being explored.