CVV2 is a number printed in the signature area of ??the Visa/Master Card card. It is the 3 digits after the credit card number. The last three digits we usually see on the back of credit cards are actually CVV2, not the CVV code.

Credit card security code is a security code for credit cards when conducting online or telephone transactions. It is usually a 3 or 4-digit number printed on the credit card, and the location of the printing will vary on different types of cards. It is often used to prevent credit card fraud by verifying that the payer owned the credit card at the time of the transaction.

Generation algorithm:

1. CVV password verification means that commercial banks add custom algorithm verification codes to the bank card number encoding rules and magnetic stripe data formats they use. Related The bank card is also called a CVN bank card.

2. CVV information is stored in the track of the magnetic stripe bank card. Based on the card number, track master account number, card-issuing bank logo code and other information, it is encrypted through a special encryption algorithm customized by each bank. Each step All are encrypted using CVKA technology to obtain the verification code. Since the encryption algorithms of different banks are different, some counterfeit cards illegally produced using the obtained bank card information can be identified and cannot be used when the card issuer decrypts them.