When Blockchain Meets Urban Rail Transit: Current Prospects, Case Studies, and Future Challenges

Thanks to the vigorous development of artificial intelligence, urban rail transit (URT) is undergoing a new round of intelligent upgrades. While its intelligence level is improving, URT suffers from a weak trust foundation, high data sharing costs, and low collaboration efficiency. Driven by outstanding features of decentralization, resilience against tampering, and traceability, blockchain can provide a safe and efficient value-trust exchange infrastructure for URT. This article focuses on the current prospects, case studies, and future challenges of blockchain-empowered URT. We first introduce blockchain fundamentals and mainstream blockchain platforms, comparing the technology's advantages and highlighting the motivation of using it in URT. The prospects of using blockchain in the lifecycle of URT, which includes planning and construction, operation and management, control and security, and upgrading and transformation, are explored. Furthermore, a concrete case study of using blockchain in a distributed authentication scheme for URT is described. Extensive testing results show that the proposed blockchain-based distributed authentication scheme can enhance the security of the train control system without sacrificing communication performance. Finally, we summarize the challenges and problems when using blockchain in future URT systems.