Smart contract for secure billing in ride-hailing service via blockchain

Ride-hailing service is gaining an increasing popularity due to its great advantages on fare estimation, automatic payments, and reputation ratings. However, how to build the trust between the driver and the passenger and achieve the secure billing still remains an open challenge. This paper proposes a novel secure billing protocol which removes the presence of the online third party by a smart contract on a publicly-verifiable two-party blockchain. In the proposed secure billing protocol, the driver and the passenger generate a blockchain which contains information about the ride. The driver and the passenger measure their own trajectories respectively in rounds. At the end of each round, they exchange their trajectories of the current round. If the difference of trajectories is within a threshold, they jointly compute the fare of current round. After completing the computation, the passenger pays the driver the fare of the current round via a micropayment channel. The driver and the passenger end each round by adding the information generated in this round into the blockchain. The blockchain can be considered as an evidence of the ride since it contains all the information of the ride. We evaluate the performance and the effectiveness of the proposed protocol via extensive experiments and detailed analysis.