Credit card security code is the security code of credit card for online or telephone transactions. Generally, it is a 3-digit or 4-digit number printed on a credit card, and the printing position of different types of cards will be different. It is usually used to prove that the payer has a credit card at the time of transaction, thus preventing credit card fraud.

CVV information is stored in the track of magnetic stripe bank card. According to the information such as card number, track main account number and logo code of issuing bank, it is encrypted by special encryption algorithm defined by each bank, and every step is encrypted by CVKA technology to get verification code.

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The reason why a CVV code is added on the back of the card is to confirm that the card is really in the cardholder's own hand. So when you swipe your card outside, be careful not to let people see it easily, especially to write down three digits, so as not to steal it together with the validity period of the card number and then steal it online.

Because the encryption algorithms of different banks are different, some fake cards illegally made by using the obtained bank card information can be identified and cannot be used when the issuing bank decrypts them.

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