The CVV code of CCB credit card is a set of numbers printed on the signature column on the back of the credit card, also called credit card security code. It is a 3-digit or 4-digit number generated by the card number, expiration date and service constraint code, and is generally written in the 2-track custom data area of the card magnetic stripe. That is, the last 3-4 digits of a string of numbers behind the signable area on the back of the card: CVV information is stored in the track of the magnetic stripe bank card, and is encrypted by a special encryption algorithm defined by each bank according to the card number, track master account number, issuer identification code and other information, and every step is encrypted by CVKA technology to obtain the verification code.

Under normal circumstances, you can spend money by swiping a bank card. Then this kind of consumption is also the safest. After all, almost all bank cards are chip cards now, and the risk of being stolen is greatly reduced. If you still have a magnetic stripe card, it is recommended to change it to a chip card as soon as possible.

Under normal circumstances, most people will bind the bank card with various payment software, and then scan the code directly when paying, and then choose the bank card. In fact, this payment method is very safe. However, if you choose online banking payment, the risk of theft will be great. Shopping with online banking generally requires only the card number, security code and verification code to complete the transaction, while some Haitao websites can pay successfully without verification code, so this risk is great. Especially credit cards, because credit cards have overdraft function and overrun function, you can spend successfully even if you have no money in your card.

But bank cards are different. If there is no money in the bank card, the other party can't steal it anyway Therefore, when a credit card is consumed online, it only needs the card number, expiration date and security code, and it can be paid successfully without a verification code. Therefore, the security code of credit card must be protected. Remember not to expose your bank card information in public or online. Although you think it's nothing, it's normal if it is used by criminals, information is leaked and bank cards are stolen, so be sure to pay attention.

The security code of the bank card is also called CVV2 code, and there are seven digits in the upper right corner of the signature column on the back of the bank. But when paying, generally only the last three digits of the security code are needed. Moreover, online payment needs anti-counterfeiting code, so you must protect your bank card information, and don't just take photos of your bank card online, otherwise the information will be easily leaked.