The credit card security code is a set of 3 or 4 digits on the credit card. Its generation method is to extract, arrange and then calculate the service code through a series of complex algorithms. This set of numbers is in the bank, and the holder of the bank card knows this number.
The credit card security code is equivalent to the credit card ID card, and we can use this code for consumer transactions. You don't need a password to shop on overseas websites. As long as the buyer provides the account number and the merchant signs a contract with the bank, you can complete the telephone transfer without the credit card password and only with the security code.
Extended data:
Anyone who has used a credit card should know that online use does not require entering a password.
The reporter's login to the business travel network was confirmed: as long as the consumer provides the cardholder's name, ID number, credit * *, expiration date, and the 3-digit verification code at the end of the signature column on the back of the card, he can pay for booking air tickets online through the credit card.
The verification code on the back of the credit card is the "last three codes" mentioned above. It is understood that credit card transactions are divided into two types: credit card transactions and offline transactions.
The former is that cardholders use credit cards to swipe their cards at POS terminals such as shopping malls and supermarkets and sign authorization. However, it is common for cardholders to book hotels, air tickets or pay online, and merchants can also use the card account number and the last three codes to complete the transaction.
The so-called last three digits are the last three digits on the back of a series of cards, which are generated by the coding rules and encryption algorithm of the issuing bank. In the process of payment, if the merchant provides the last three codes to the bank, the transaction is allowed.
References:
Baidu encyclopedia-credit card security code
-Credit card, pay attention! The last three yards are hidden. Don't show it.