HOTP is a counter-based one-time password method that generates verification codes from a shared secret and an incrementing counter. It matters because one-time password systems vary in how they produce codes and how they handle synchronization.
What is HOTP?
HMAC-Based One-Time Password, or HOTP, creates a new code whenever the shared counter advances rather than based on time. It is less common than TOTP in many modern user-facing apps but still useful in some token and hardware workflows.
What HOTP Commonly Supports
Common uses include hardware tokens, legacy MFA systems, event-driven one-time codes, and specialized authentication devices.
HOTP vs. TOTP
HOTP changes codes based on a counter or event sequence. TOTP changes codes based on time windows.
Frequently Asked Questions
Why is HOTP important?
Because it underlies some older or specialized MFA systems and illustrates a different one-time code model.
What is a practical challenge with HOTP?
Counter synchronization can become more cumbersome than time-based approaches in some deployments.
