自[二维码支付](http://www.wiipay.cn/)诞生以来，短短数年，已呈星火燎原之势遍布全国各地，已成为目前最为火爆的一种支付方式，下面就来了解下什么是第三方二维码支付。
Two-dimensional code payment means that the payment information is compiled into a two-dimensional code, and the user or merchant scans the two-dimensional code to obtain the payment information and complete the payment. For the principle of QR code payment, I think it can be divided into four categories according to the different payment information (paying user, payment amount, acquiring merchant) contained in the QR code: payment account QR code payment, payment account QR code Payment, order QR code payment, scene QR code payment, the following article will be introduced separately.
1. Payment account QR code payment
Payment account QR code payment , the principle is: QR code is the payment account. The most single-line case is the WeChat payment (or Alipay, etc., the same below) swiping card payment for supermarkets and convenience stores; when paying, the user shows the payment code to the cashier, and the cashier scans the payment code with a scan code gun to complete the payment. Attentive readers can note that the payment code of WeChat payment is actually a string of numbers representing the paying user. The payment platform can determine the unique payment account through this string of numbers (although the QR code is updated every minute, it does not affect its uniqueness. The ability to determine the payment account), so that you can know which account is deducted; the payment amount and collection merchant are generated by the merchant's back-end system and sent directly to the payment platform.
How to understand the QR code payment of the payment account ? In fact, the payment account QR code payment is equivalent to the card number in the POS card payment; even the overall principle is similar to the POS card payment.
Second, the payment account QR code payment
collection account QR code payment , the principle is: the QR code is the collection account. This is the most common way to pay by QR code. The payment merchant displays the QR code to the paying user. When the user scans the QR code using the QR code payment app, the payment platform presents the user with a page for entering the amount. The user enters the amount and submits it to complete the payment.
Payment account QR code payment case
In the QR code payment of the payment account, the QR code represents the acquiring account opened by the merchant on the payment platform. When the user scans the QR code of the payment account, the payment platform parses out the payment merchant from the QR code and the payment account from the logged-in user; after the user enters the amount and submits it, the payment platform can know the payment amount. Therefore, the three elements of payment (paying user, payment amount, acquirer) are complete: which user's money is deducted, how much is deducted, and which merchant is deducted.
It is easy to notice that, unlike the QR code of the payment account (automatically updated every minute), the QR code of the acquiring account can remain unchanged for a long time, because no one will rush to send money to the receiving account represented by this QR code .
Third, the order QR code payment
Order QR code payment, the principle is: the QR code is the order (order amount, acquirer). WeChat Pay / Alipay have launched order QR code payment. In many subway stations, we can see self-service vending machines that support order QR code payment. Each merchant has a code. After the user scans the code using WeChat (Alipay), it can be completed Pay for goods. For another example, after selecting Alipay on the PC, the order QR code will be presented. After the user scans the code using the Alipay APP, the payment can be completed on the mobile phone.
Order QR code payment case
So, what is the essence of order QR code payment? The essence is that the QR code contains the order information (order amount, receiving merchant). When the user scans the QR code of this order using WeChat (or Alipay, etc.), WeChat parses the order amount and the receiving merchant represented by the QR code, so WeChat also knows how much money is deducted and to which merchant From which user to deduct money, it is obviously easy to locate the currently logged-in user.
Fourth, scene QR code payment
scene QR code payment, the principle is: QR code is the scene. In the scene QR code payment method, the QR code no longer is limited to represent pure payment information (paying user, payment amount, acquirer), but also contains rich scene information, which has strong scalability.
