3D Secure is an authentication method designed to reduce fraud and increase security for online card transactions. Originally sponsored by Visa under the ‘Verified by Visa’ brand, Mastercard and other networks adopted the ‘3D Secure’ protocol and offer it to merchants worldwide. The name derives from the use of 3 domains (the acquiring bank domain, the issuing bank and an infrastructure domain) to provide greater security to online payments, although the extra validation and related consumer friction remains a topic of debate among merchants and security experts.