Security, authentication, payment WG

Payment authentication is the process of confirming a customer's identity through at least one of the following authentication factors: knowledge, inherence, ownership, and user location.
Knowledge is the most common category used for transaction authentication.
The knowledge factor is the information that only the cardholder possesses: personal password, PIN, a secret word like your mother's maiden name, your favorite vacation spot, etc. A knowledge-based authentication factor is also known as the Challenge-Handshake Authentication Protocol (CHAP).