Read more about HOTP and TOTP here: https://en.wikipedia.org/wiki/HMAC-based_One-Time_Password https://en.wikipedia.org/wiki/HMAC-based_One-Time_Password http

Read more about HOTP and TOTP here: https://en.wikipedia.org/wiki/HMAC-based_One-Time_Password https://en.wikipedia.org/wiki/HMAC-based_One-Time_Password https://en.wikipedia.org/wiki/Time-based_One-Time_Password https://en.wikipedia.org/wiki/Time-based_One-Time_Password Implementations vary, but TOTP was developed on top of HOTP and presents a standardized method to expire OTP codes.