2. Generation algorithm: CVV password verification means that commercial banks add the verification code of self-defined algorithm to the coding rules of bank card numbers and magnetic stripe data formats they use. Related bank cards are also called CVN bank cards. CVV information is stored in the track of magnetic stripe bank card. According to the card number, tracking main account number, issuer identification code and other information, it is encrypted by a special encryption algorithm customized by each bank. Use cvka technology to encrypt every step of obtaining verification code. Due to the different encryption algorithms of different banks, some fake cards illegally made by using the obtained bank card information can be identified when the issuing bank decrypts them and cannot be used.
First of all, different credit card security codes have different locations:
65438 +0. Visa card has 3 digits, which are printed after the 4 digits of the card number in the signature column on the back of the credit card.
2. MasterCard has 3 digits, printed on the back of the credit card, and 4 digits after the card number in the signature column.
I found that the card has three numbers, which are printed in the signature column on the back of the credit card.
4. American Express Card has four numbers, which are printed on the front of the credit card and above the credit card number.
5. UnionPay card has 3 digits, printed on the back of the credit card, and 4 digits after the card number.
6.JCB card has 3 digits, which are printed on the back of the credit card after the 4 digits in the signature column.
Second, how to keep it so as not to leak:
1. Just after you get the credit card, you can use encryption software (remember not to record the card number and CVV code together) to remember the three digits (CVV2 code) on the back of the card, and then stick a sticker or adhesive with a security code that is easy to tear to prevent leakage.
2. Make sure that the card will not leave the body. Please keep the card in sight when spending, and don't give it to others to brush it for others, so as to avoid the information of the card being leaked.
Pay more attention to those unfamiliar customer service calls. Once we are asked three numbers, we should also be warned. Don't reveal the card information casually.
4. Don't waste some unknown JW machines.
5. Turn off all credit card transaction functions as soon as the mobile phone is lost. Special circumstances, loss reporting card.
6. Never give your card to strangers or fly abroad to spend money.