A card-payment authentication protocol that lets an issuer assess a card-not-present transaction and, when risk warrants it, challenge the cardholder before authorization. Modern versions support risk-based, low-friction flows as well as step-up authentication.
Category: authentication. Part of the Identity Technologist Glossary — more than 200 practitioner-grade definitions covering identity verification, KYC/AML, biometrics, fraud prevention, and compliance. See all terms at https://identitytechnologist.com/glossary.