Do I Have to Sign the Back of a Credit Card?

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 printing position of different types of cards will be different. It is often used to verify that the payer owned the credit card at the time of the transaction, thereby preventing credit card fraud.

Credit card security code

CVV password verification means

The security code of the VISA card is called CVV2 (Card Verification Value 2), which has 3 digits and is printed on the back of the credit card on the signature bar on the back of the card number 4 digits. ^[3]

The credit card security code is equivalent to the credit card's ID card, and we can use this code for consumer transactions. No password is required for shopping on overseas websites. As long as the buyer provides an account number and security code, the transaction can be completed, and there are also domestic merchants and banks to sign a contract, and the credit card password can be used to complete the phone transfer without the security code. Therefore, you must keep your credit card well, and don't let the credit card leave your sight when spending, so as to prevent others from remembering your credit card account number and security code. ^[4]

On March 22, the vulnerability reporting platform Wuyun.com released two vulnerability reports in succession, claiming that Ctrip's secure payment log was downloadable, leading to the leakage of a large number of users' bank card information. Ctrip responded that night, saying that this was a short-term vulnerability that occurred during the technical debugging process, and it was fixed within two hours. The user information security was not affected.

On March 23, Ctrip issued two successive statements stating that Ctrip had contacted major banks. As of March 23, there had been no stolen credit cards, and 93 potential risk users had been notified to change cards. ^[5]

The credit card security code is the same as the CVV code, which is the card verification value obtained by the same algorithm, but when the card is generated, the CVV code is written into the magnetic stripe, and the credit card security code is written on the card.

CVV codes are checked during online transactions (card swipes), and credit card security codes are more checked during off-site transactions or without card transactions.