PriParkRec: Privacy-Preserving Decentralized Parking Recommendation Service

Insufficient parking space and traffic congestion are important usual suspects in our urban life. Organisation and managing available parking spaces have raised a lot of awareness. Traditional centralized parking approaches are with an insidious single point of failure and unsuitable for large organization because the manager is overburdened with authority and responsibility. The malicious service provider enables to (i) track the precise mobility patterns of citizens. (ii) collect the data to infer privacy-sensitive information, e.g., where the parking requester (i.e., driver) socialize, work, and live; (iii) analyze trajectories to monitor the location of the driver for entertainment (e.g., discovering one-night stands). To design a decentralized smart and practical parking platform without compromising the privacy of the entities is an urgent issue for the smart city. Blockchain (or distributed public ledger technology) is a near-ideal decentralized and distributed solution for centralized car-parking systems. However, most of the existing car-parking solutions on top of blockchain ignore to protect the privacy of drivers during parking spot detection and matching phases while cannot maintain the property of anonymity of the drivers. In this paper, an efficient and privacy-preserving car-parking recommendation service platform, named as PriParkRec, along with the proof-of-concept solution to protect the requester's privacy in PriParkRec while maintaining most of the bene- fits of current parking-slot-sharing service, i.e., accountability, (anonymous) authentication, (anonymous) payment, and repu- tation ratings. Indeed, PriParkRec service relies on well-known privacy-enhancing cryptographic building blocks (e.g., oblivious PRF, private set intersection, anonymous credentials, anonymous payment, and smart-contract, etc), these building blocks are carefully integrated together to achieve privacy and security goals to revolutionize the existing car-parking service system coming with the private blockchain and industrial internet of things (IIoTs) technologies.