The last three digits on the back of the credit card are the last three digits, which is a security code used for online payment. Some cards have been stolen by the network, which may be that the last three digits are known by others ~ \ x0d \ x0d \ last three digits \ x0d \ 1. Define \ x0d \ \ x0d \ CVC. \x0d\\x0d\2。 \ x0d \ \ x0d \ (card verification value), that is, credit card verification value. The display position is on the back of the credit card, and the top of the signature is displayed in italics. The first four digits are the card number and the last three digits are the verification code, that is, the last three digits. Note that this verification code does not refer to the password of the credit card, just enter the bank card number and its last three digits, as well as the validity period of the credit card, and there is no password at all. At noon yesterday, the customer service staff in Ctrip.com told the reporter that the information needed to buy a plane ticket by credit card is: card number, credit card validity period, "last three" verification codes, and cardholder ID number. \ x0d \ x0d \ The use of credit cards can be divided into "swipe transaction" and "offline transaction". In the former, the cardholder swipes the card at POS terminals such as shopping malls and supermarkets, signs the authorization, and then completes the transaction. Offline transactions are common when cardholders book hotels, air tickets or pay online. The merchant also provides the credit card account number and the last three codes through the POS system to complete the transaction. The last three digits of \ x0d \ x0d \ are the last three digits on the back of a series of cards, which are generated by the coding rules and encryption algorithm of the issuing bank. In the payment process, if the merchant provides the last three codes to the bank, the bank will obtain the authorization of the cardholder to the merchant by default, thus allowing the transaction.