Authentication Factors Explained
Something you know, something you have, something you are - the three categories every authentication method falls into, and why mixing them matters.
What is MFA?
Multi-factor authentication means proving your identity with two or more different categories of evidence. What counts, what doesn't, and where it fails.
What is 2FA?
Two-factor authentication adds a second proof on top of your password. How it works, which second factors to prefer, and what it does not protect against.
What is OTP?
A one-time password is a code valid for a single use. How OTP works, the difference between counter-based and time-based codes, and where it fits.
What is TOTP?
TOTP generates a fresh six-digit code every thirty seconds from a shared secret and the current time. How the algorithm works and why clocks matter.
OTP vs TOTP
OTP is the general concept, TOTP the time-based version almost everyone uses. How TOTP and counter-based HOTP differ, and which one you actually have.
SMS vs TOTP
SMS codes depend on your phone number, TOTP codes on a secret held by your device. Why SIM swapping makes that difference decisive.