3-D Secure was developed by Visa to help make internet payments more secure. You have probably heard it being referred to as "Verified by Visa", or as "MasterCard SecureCode".
3-D Secure adds an extra security check for online payments, therefore decreasing the risk of internet fraud. This step is usually simply your bank or card provider asking you for a password, only known to you and your bank. As we don't know or capture this password, it can be used as evidence that the purchaser is indeed the cardholder.
Remember, ayondo can't manually authorise a deposit if it has been declined due to not being 3-D Secure.
If you want more information about the system, visit Verified by Visa or MasterCard SecureCode.