The HMAC is a specific, albeit special type of message authentication code that couples a cryptographic mathematical hashing function along with pre-shared secret cryptographic keys.

Other authentication mechanisms, such as the hash function message authentication code (HMAC) and digital signatures, have long been available.

Oath announced its initial effort, a hashed message authentication code (HMAC) one-time password (OTP) algorithm, in October at the Digital ID World show in Denver.

Other authentication mechanisms, such as the hash function message authentication code (HMAC) and digital signatures, have long been available.