A blockchain-based data transaction method with privacy protection and fairness

Abstract

In online trading, buyers may not be willing to reveal their identity, thus anonymous payment systems such as Central Bank Digital Currencies (CBDC) or blockchain systems may be preferred, instead of centralized payment systems. However, when relying on those payment systems, cheating or unfair behaviors from anonymous accounts should be defended against. In this paper, we propose a scheme that not only guarantees stronger customer privacy protection in terms of payment anonymity and transaction information anonymity (e.g., shopping user name, address), but also maintains the fairness in transactions. Our proposed system consists of three web systems: B2C web, M2B web, and delivery web, as well as an anonymous payment system (or blockchain, distributed ledger). The detailed models and protocols are proposed for trading, pre-payment, payment, arbitration between customers, merchants, manufacturers, third evaluators, and arbitrators. Experimental results show the low gas costs and execution time of each function on smart contract. The fairness in transactions is yet maintained because locked payment can be invoked by smart contract from oracle from the delivery web upon confirming the recipient of purchased merchandise by the customer.