The security code of a bank card is the seven numbers in front of the cardholder’s signature on the back of the bank card. In fact, the security code is the same as the mobile phone verification code. If it is a credit card, you need to use the last part of the security code to activate the credit card. Three, this security code is sometimes used when paying online with a bank card.

1. If it is a credit card, fill in the last three digits in the signature field on the back of the credit card. These three digits are the credit card security codes - CVV2 and CVC2. Among them, the security code of Visa is called CVV2 (Card Verification Value 2); the security code of MasterCard is called CVC2 (Card Validation Code 2).

2. The credit card security code is equivalent to the credit card’s ID card. We can use this code to conduct consumer transactions. Shopping on overseas websites does not require a password. As long as the buyer provides an account number and security code, the transaction can be completed. In China, there are also merchants that have signed contracts with banks to complete phone transfers without a credit card password and only with a security code. Therefore, everyone must take good care of their credit cards and keep them out of their sight when making purchases to prevent others from remembering your credit card account number and security code.

3. The security code is extracted by the bank from the card account number, validity period, and service code, and then calculated through a series of complex algorithms after arranging them. After this set of numbers is generated, only the issuing bank and the bank card holder know what the number is. Therefore, this number is very important to the credit card holder.

Extended information:

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 bank cards Also known as CVN bank card.

CVV information is stored in the magnetic 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 uses CVKA technology encrypts and gets 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.

Reference material: Credit card security code Baidu Encyclopedia