Time-based One-Time Password

TOTP - Time-based One-time Password Algorithm is an extension of the HMAC-based One Time Password algorithm HOTP to support a time based moving factor. A moving factor is a value that must be changed each time a new password is generated in order to ensure that a different password is always generated. So a password generated at 12:00:01 will be different than one generated at 12:00:31 even if other items used to generate it are the same. Note: the time difference only cares about intervals in 30 second amounts. So a password generated 12:00:01 will be the same as one generated at 12:00:15 and 12:00:29. TOTP is an Internet Engineering Task Force standard and a cornerstone of Initiative For Open Authentication (OATH).

Android - Google Authenticator


Android - Other software


iOS - Google Authenticator


Windows phone - Authenticator


Google Authenticator J2ME


J2ME