Some credit card companies have started requesting extra security information when processing payments. This is for the protection of their customers and has nothing to do with our website. Visa and MasterCard in particular have developed authentication procedures to improve online transaction security.
Sometimes a valid order attempt is refused by Adyen, our credit card processing company. This happens especially to our US-based clients. The bank that issued the card is trying to protect the customer (you) by blocking the card when it is used overseas.