Some credit card companies use a system called 3-D Secure (3DS) that adds an extra step to transactions that are carried out on the Internet. Visa and MasterCard tout their security, but researchers are questioning their efficacy. 

When making a purchase, online shoppers are confronted with a validation check that requires them to supply a password—in addition to the standard security code that is on the card itself—in order to prove that they are the real owner of a credit card. Systems built on 3DS are better known by their brand names, which include Verified by Visa and MasterCard SecureCode.