Learn about two-factor authentication
Understand what your authenticator is doing before changing its settings. Start with the basics, then follow the guide that matches your task.
What is two-factor authentication?
Two-factor authentication adds another kind of proof to a sign-in. An authenticator code is one common method, but it is not the only one.
Open GUIDEHow TOTP codes work
A TOTP generator and the service checking it use a shared secret and time-based settings to calculate matching codes.
Open GUIDETOTP vs HOTP
TOTP and HOTP both generate short authentication codes from a secret. Their main difference is what makes the code move to the next value.
Open GUIDEUnderstanding an otpauth URI
An otpauth URI is a setup link used by many authenticator apps. It carries the information an app needs to configure a code generator.
OpenThe basics
Learn the difference between a password, a setup key, and a temporary authentication code.
Code types and setup links
Explore time-based and counter-based codes, then learn how an otpauth link carries setup information.