B-Ride: Ride Sharing with Privacy-preservation, Trust and Fair Payment\n atop Public Blockchain

Abstract

Ride-sharing is a service that enables drivers to share their trips with\nother riders, contributing to appealing benefits of shared travel costs.\nHowever, the majority of existing platforms rely on a central third party,\nwhich make them subject to a single point of failure and privacy disclosure\nissues. Moreover, they are vulnerable to DDoS and Sybil attacks due to\nmalicious users involvement. Besides, high fees should be paid to the service\nprovider. In this paper, we propose a decentralized ride-sharing service based\non public Blockchain, named B-Ride. Both riders and drivers can find rides\nmatch while preserving their trip data, including pick-up/drop-off location,\nand departure/arrival date. However, under the anonymity of the public\nblockchain, a malicious user may submit multiple ride requests or offers, while\nnot committing to any of them, to discover better offer or to make the system\nunreliable. B-Ride solves this problem by introducing a time-locked deposit\nprotocol for a ride-sharing by leveraging smart contract and zero-knowledge set\nmembership proof. In a nutshell, both a driver and a rider have to show their\ncommitment by sending a deposit to the blockchain. Later, a driver has to prove\nto the blockchain on the agreed departure time that he has arrived at the\npick-up location. To preserve rider/driver location privacy by hiding the exact\npick-up location, the proof is done using zero-knowledge set membership\nprotocol. Moreover, to ensure a fair payment, a pay-as-you-drive methodology is\nintroduced based on the elapsed distance of the driver and the rider. Also, we\nintroduce a reputation-based trust model to rate drivers based on their past\ntrips to allow riders to select them based on their history on the system.\nFinally, we implement B-Ride in a test net of Ethereum. The experiment results\nshow the applicability of our protocol atop the existing real-world blockchain.\n