Privacy-Preserving Smart Parking System Using Blockchain and Private Information Retrieval

Searching for available parking spaces is a major problem for drivers in crowded cities, causing traffic congestion, air pollution, and wasting drivers' time. Smart parking systems enable drivers to solicit real-time parking information and book parking slots. However, current smart parking systems require drivers to disclose their sensitive information, such as their desired destinations. Moreover, existing schemes are centralized, which makes them vulnerable to bottlenecks and single point of failure problems and privacy breaches by service providers. In this paper, we propose a privacy-preserving smart parking system using blockchain and private information retrieval. First, a consortium blockchain is created by different parking lot owners to ensure security, transparency, and availability of the parking offers. Then, to preserve the drivers' location privacy, we adopt private information retrieval technique to privately retrieve parking offers from blockchain nodes. In addition, a short randomizable signature is used to allow drivers to authenticate for reserving available parking slots from parking owners anonymously. Our evaluations demonstrate that our proposed scheme preserves drivers' privacy with low communication and computation overheads.