A Blockchain-based Online Transaction System for Physical Products Trading with Fairness, Privacy Preservation, and Auditability

Fair trading, privacy preservation, and auditability are core requirements for any online transaction system. Existing systems achieving these requirements mainly focus on digital products and rely on a centralized design. However, these systems are unsatisfactory for physical products and suffer from the single-point-of-failure problem in reality. In this paper, we analyze the inherent characteristics of actual online transaction systems for physical products, where we point out that express could not be fully trusted in reality. Specifically, the express is a rational entity and could launch various attacks to break the security or violate user’s privacy for profits. We propose PBOT, which is a blockchain-based online transaction system for physical product trading with fairness, privacy preservation, and auditability. Our security analysis and performance evaluation of its core modules demonstrate that PBOT is secure, feasible, and efficient.