Despite using it every day, do you still feel uneasy about digital payments? Scientists at the University of Vienna in Austria have designed an unconditionally secure system that combines modern encryption technology with the basic characteristics of quantum light. The team conducted the first demonstration of "quantum digital payment" in a real environment, and related research was published in the recent Nature Communication. In today's payment ecosystem, customer sensitive data is replaced by random number sequences, and the uniqueness of each transaction is guaranteed through classic encryption methods or code. However, opponents with powerful computing resources can crack and recover customers' private data to make payments on their behalf. The team demonstrated the unconditional security of digital payments by utilizing the quantum properties of photons. In an experiment, researchers demonstrated that every transaction cannot be replicated or transferred by malicious parties, and that users' sensitive data remains private. In order to achieve absolutely secure digital payments, scientists have replaced classical encryption techniques with single photon quantum protocols. In classic digital payment transactions, customers share a classic code (called a password) with their payment provider (such as a bank or credit card company). Then the password is passed between the customer, merchant, and payment provider. In the demonstrated quantum protocol, the password is generated by having the payment provider send specially prepared single photons to the client. For the payment process, the client measures these photons, where the measurement settings depend on the transaction parameters. Since the Quantum state of light cannot be copied, the transaction can only be executed once. In addition, any deviation from the expected payment will alter the verification results, making the digital payment unconditionally secure. The researchers successfully realized quantum digital payment on the urban optical fiber link between two university buildings in central Vienna, 641 meters away. Currently, digital payment can be completed in just a few seconds. In many aspects of daily life, digital payments have replaced physical banknotes. Although digital payment has the advantages of being easy to use, unique, Tamper resistance and untraceable, it also needs to be able to resist digital attacks and Data breach - which is the biggest defect of digital payment in addition to the limited coverage and the difficulty in controlling digital money. Now researchers have applied quantum encryption to digital payments and successfully demonstrated it, adding a heavyweight to the digital payment end of the payment balance. (New News Agency)