The generation method of credit card security code is that the bank extracts the account number, validity period and service code of the card, arranges them and then calculates them through a series of complicated algorithms. After this set of numbers is generated, only the issuing bank and the holder of the bank card know what this number is. Whether it belongs to VISA or MASTER credit card, the principle of generating security code is the same. The security code of credit card is mainly used as verification code for online transaction or credit card cancellation.
The three digits on the back of a credit card are as important as the cardholder's signature and belong to the "secret" of the credit card, so the cardholder should keep them properly. It is suggested that credit card holders who frequently conduct online transactions must ensure the safety and legality of the merchants who conduct transactions with them, and prevent the digital information on the card surface from being leaked to irrelevant personnel, otherwise it will bring credit card security risks to themselves. The last three digits also play a very important role in preventing the card from being cloned. Because if criminals get credit card account information and copy the card, but don't copy the "last three codes" information, even if they know the password, they will be rejected by the ATM machine when withdrawing money.
Security code protection instructions
1. After getting a new card, it is recommended to stick a security code with a small sticker to prevent leakage.
2. In recent years, I have received any information (telephone, SMS, WeChat, QQ, email, etc.). By obtaining the security code, all the people who ask for the security code are liars. Don't be cheated.