3-D Secure is a credit card authentication program implemented by Visa (Verified by Visa) and MasterCard (MasterCard SecureCode) to reduce fraudulent purchases by verifying purchaser identity during online transactions. The benefits of implementing 3-D Secure include a reduction in disputed transactions and chargebacks and their resulting financial expense.

The objective of 3-D Secure is simple - to assure the vendor that the card issuer bank believes that it is the legitimate cardholder who is using the card to make a purchase. The issuer bank authenticates cardholders by their passwords.