TOTP

TOTP stands for Time-based One-Time Password. It is an algorithm that generates a one-time password from a shared secret key. The password is available for a short period of time after retrieval, after which it can no longer be used and a new password is generated.

The TOTP algorithm is an extension of the HMAC-based One-Time Password (HOTP) algorithm and has been adopted as Internet Engineering Task Force (IETF) standard RFC 6238. TOTP is used in a variety of two-factor authentication systems, providing an extra layer of security in addition to passwords.