Double offline payment refers to the payment realized by NFC technology when both terminals of digital RMB are offline in the transaction process. At first glance, it is of little use, but if it is in a special environment, such as mountainous areas, underground garages, or even some natural disasters, the function of this pair of offline payment is very meaningful.
So if natural disasters take a long time, such as the rainstorm in Henan, and some areas can't get the signal within dozens of hours, is it still useful to pay offline?
The answer is very difficult. There is a premise for dual offline payment, that is, the equipment must have at least electricity, and it can't be used naturally without electricity. In the case of natural disasters, if the signal is lost, it often means that the power of mobile phones and other equipment is limited, and the function of wallet will naturally be lost without electricity.
Then, if I find a device that can supply power continuously, such as a generator, will dual offline payment work?
The answer is still-it doesn't work!
This is mainly a technical problem. At present, the function of hardware wallet, the carrier of digital RMB, is still being modified and improved. In fact, dual offline payment is somewhat similar to blockchain technology. Every transaction needs to be calculated once and data is stored. This data naturally cannot be just a simple digital change, but a long string of codes consisting of 0 and 1, and with the increase of operation times, the difficulty of calculation is also rising, that is to say, The more times of offline payment, the more storage space and computing power of equipment are needed. After reaching a certain number of times, the transaction speed will be greatly reduced, which will seriously affect the experience. Therefore, the current digital RMB dual offline payment is limited by the number of transactions, and it is unrealistic to use dual offline payment for a long time.
At the same time, there is also the problem of "double spending". If we can't prevent the backup and data replication of offline transactions, then "double spending" (using a sum of money twice or even many times) can't be solved.
After all, the dual off-line payment of digital RMB is only an emergency measure for special circumstances. If it really needs to be used for a long time, I am afraid cash will work better.