With the continuous increase in the number of credit card users and the continuous development of technology, the security issues faced by credit cards under the mechanism of consumption first and payment later are becoming increasingly prominent. The security problems of today's credit cards are mainly reflected in the following aspects.

1. Third party: Unlawful third parties use credit cards or counterfeit cards to consume and withdraw cash through means such as theft, copying, ATM fraud, forgery, false identity and false declarations, and provide credit card holders and banks with cause losses.

2. Cardholders: Poor storage/handling of cards (expired/expired credit cards are not destroyed, or lost credit cards are not immediately invalidated, etc.), and unintentional theft or deception of personal identity information . In order to avoid such problems, citizens cannot easily provide personal identity information to others, let alone entrust others to apply for credit cards.

3. Consumer merchants: The waiter overcharges the cardholder during the consumption process, or steals his/her credit card information to spend at other merchants. This can happen regardless of whether it is a physical store or an online virtual merchant; unscrupulous merchants use domain names or emails close to well-known stores to induce consumers to log in to their own websites and submit payment information. The owner of the specialty store forged customers' shopping invoices and then asked the bank for money.

4. Inside the bank: Criminals within commercial banks take advantage of their authority to steal credit cards, or steal credit cards that have been stolen, pretending to be customers to withdraw money or use cards to make purchases; or steal large sums of cash, steal computer systems, and maliciously intrude Customer’s basic information/transaction information.

5. Transaction system and mechanism: As long as the transaction system and mechanism are created by people or guided by people, human errors and negligence will not occur; no matter how strict the transaction mechanism is, it must be confirmed from the A world-class trading system that reaches settlement still has the possibility of being invaded. The so-called "invasion" actually has levels.