3-D secure is a process that is used to offer greater security for online payments by credit card. If you use the Visa circuit it is called Verified by Visa. MasterCard offers the same service called MasterCard SecureCode. For this, the customer uses a password. The first time you use this service, the user is redirected to the bank's website to create a password. This same password will be used for all future purchases. If you are not sure that your credit card has a 3-D secure option, please contact your bank. The use of the 3-D secure is free for the user.