With the development of society and the advancement of science and technology, the standard of trade has expanded from reality to virtual, and the market has expanded from tangible to intangible, and has been enriched and improved. The core of trade is exchange. Exchange is the unification of the two opposing processes of delivery and payment. The principle of exchange follows between the normal subjects of freedom and equality is equivalence and synchronization. Synchronous exchange means that delivery and payment are mutually conditional and are the guarantee of equivalent exchange.
The exchange process is divided into an exchange protocol phase and a target transfer phase. The subject matter includes goods, services, labor, technology, information, etc. The exchange agreement is a so-called equivalent value that the opposing parties can achieve and agree with each other. The transfer of the underlying ownership is conditional on the synchronized interaction of the considerations, so the exchange is implemented in a dynamic process. In practice, synchronous exchange is easy to implement for off-the-shelf face-to-face transactions; but in many cases, due to the flow acceptance of the transaction target (such as the flow of goods and goods, the transformation of service labor) requires the process, the asynchronous flow of goods flow and capital flow The contradiction of separation is inevitable, and synchronous exchange is often unrealistic.
In the case of asynchronous exchange, the party that receives the consideration first is likely to violate the ethics and agreement and undermine the principle of equivalence exchange. Therefore, the party that pays the consideration first will often be subject to the person, and will be in a passive and weak position and bear the risk. Asynchronous exchanges must be accompanied by credit or legal support for the exchange to be completed successfully. Virtual credit is an uncertain factor and must be determined by real security. Synchronous exchange can avoid the risk of non-equivalent exchange.
As a payment in one of the two opposing processes in the exchange, subject to conditions and methods, the current payment method is often a simple immediacy direct transfer, one-step payment. For example, the domestic settlement method has different classifications according to different standards. Here, according to the settlement form, it is divided into banknote settlement, bill settlement (including cheque, promissory note, bank draft, acceptance bill), and remittance settlement (including wire transfer, online payment). In addition to the acceptance of the bill of exchange, the rest can be regarded as cash settlement. Banknote settlement and bill settlement are suitable for face-to-face spot transactions, which can realize synchronous exchange (the check is a malicious refund of individual credits and other factors, resulting in asynchronous exchange), and the exchange settlement is suitable for the spot transaction, for the partition or futures. Transaction, without credit guarantee and legal support, the one-time payment in an instant makes the asynchronous exchange easy to trigger the risk of non-equivalent exchange.
