3-D Secure is a protocol designed to be an additional security layer for online credit and debit card transactions. The name refers to the “three domains” which interact using the protocol: the merchant/acquirer domain, the issuer domain, and the interoperability domain
The 3-D Secure is a 2 step check performed initials by the card scheme (Visa/MasterCard) and then the card issuing bank.
The card scheme will verify whether the customer’s card has been enrolled by the issuing bank into the 3-D Secure scheme. If the card has been enrolled, we will be able redirect the customer to their card issuing bank for authentication. The card issuing bank will then send us a response confirming the result of the authentication check.
Below is a table of possible different 3-D Secure responses:
| Enrol | Auth | Description |
|---|---|---|
| Y | Y | Fully authenticated |
| Y | N | Card enrolled into the scheme, customer failed to authenticate |
| Y | A | The card is enrolled; the card issuing attempted to authenticate the customer but were unable to verify the status |
| Y | U | The card is enrolled; the card issuing bank were unable to attempt the authentication |
| N | The card is not enrolled into the scheme, authentication is not possible | |
| U | We were unable to verify the enrolment status of the card |
