Cannot be disclosed. The three numbers on the back of the credit card are the CVV2 code, which is as important as the credit card password, but it is easily overlooked. You must be vigilant and do not leak the number easily.

This type of fraud often informs the victim in the name of bank customer service that the credit limit can be increased. After obtaining consent, the victim will be asked to provide the credit card number, expiration date and three-digit CVV2 code on the back of the card, and then will be required to complete a formality. The fee is charged to the card to "activate" it. If the victim finds it troublesome at this time and requests to cancel the limit upgrade, the other party will ask the victim to receive a verification code and inform him that the operation has been "cancelled."

In fact, once the victim informs the received verification code, the criminal can complete the fraud. The three-digit CVV2 code on the back of the credit card is the security code of the credit card when conducting online or telephone transactions. It is usually used to confirm that the payer actually holds the credit card during the transaction.

Since some websites, especially overseas websites, do not require a password when paying on a credit card network, and transactions can be completed using only the card number, validity period and CVV2 code, the CVV2 code is almost as important as the password. Therefore, you must be vigilant. It is best to go to the bank counter in person and do not leak the CVV2 code easily.

cvv2 is the credit card security code, which 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.

cvv2 is the credit card security code, which is a set of 3 or 4 digits on the credit card. The generation method is that the bank extracts the card account number, validity period, and service code, arranges them, and then calculates them through a series of complex algorithms. After this set of numbers is generated, only the issuing bank and the bank card holder know what the number is.

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. The relevant bank cards are also called CVN bank cards. 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 is 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.