BlockToll: A Hierarchical Blockchain Based Secure Toll Collection System for Intelligent Transportation System

With the increase in urban population more and more vehicles are coming to road. Along with the recent advancement of technology, the transportation system is also getting modernized like other systems. Intelligent Transportation System (ITS) is the modern way of transportation, and toll collection is an integral part of it. Toll collection devices and roadside units are installed in open public areas along the roadside. Therefore, these devices are easily accessible by intruders and are prone to different kinds of attacks. The literature study shows that the current road toll collection systems suffer from various security risks and lack in network features like distributed nature, transparency, and more; hence, the system needs to be updated. Also, a few existing blockchain-based toll collection systems do not keep vehicle trip information private. A secure, back-traceable, and trustworthy uniform mechanism should be adopted to overcome those problems. Blockchain can be one of the solutions for doing so. In this paper, a multilevel blockchain-based toll collection system has been proposed. To keep driver and vehicle information private, the Conditionally Anonymous Ring Signature scheme has been used. For faster performance and to ensure the security of devices at toll plazas, Proof-of-Authority consensus has been implemented. Elliptic Curve digital signature is used to ensure data integrity and faster processing in resource-constrained devices. The main aim of this research is to enhance the security and enable traceability in the existing toll collection system by developing a hierarchical blockchain based system. Simulation results obtained in terms of transaction latency, throughput and gas cost shows that the proposed system is capable to handle toll collection. Experimental result shows the feasibility of implementation in the real world.