Todd has been asked by the security officer to purchase a counter-based authentication system. Which of the following best describes this type of system?

Behavioral biometrics authenticate users based on how they perform actions (e.g., keystroke dynamics or gait), which has no relation to counter-synchronized cryptographic one-time passwords.

Physical biometrics authenticate users based on physiological traits such as fingerprints or iris patterns, which is entirely unrelated to counter-based OTP generation.

Counter-based authentication is standardized in RFC 4226 as HOTP. It generates a one-time password by computing an HMAC-SHA1 hash using a shared secret key and an incrementing counter value synchronized between client and server. Each successful authentication increments the counter on both sides, ensuring every OTP is valid only once and cannot be reused.

Passphrase-to-virtual-password conversion describes cognitive or S/KEY-style passphrase schemes, not the counter-driven HMAC cryptographic process used in HOTP.