HMAC-Based One-Time Password (HOTP)

An HMAC-based One-Time Password (HOTP) is a password that utilizes an OTP algorithm based on Hash-Based Message Authentication Code (HMAC). HOTPs, similar to Time-based One-Time Passwords (TOTPs), are employed as a security measure in specialized authentication methods like two-factor authentication (2FA). The HOTP mechanism generates a one-time password using a hash function, enabling users to securely log in to various websites, often through their mobile phones using an authentication application.