Sharing Economy: Implementing Decentralized Privacy-Preserving Parking System

Recently, smart-parking systems were proposed employing blockchain technology to ensure security, transparency, and availability of services. Building on a principle of complete system decentralization, we present the concept and implementation of a privacy-preserving solution for renting parking spaces. The anonymity of users is ensured by a combination of zero knowledge proofs, commitment schemes, differential privacy and fungible tokens. We compare implementations on three different public blockchain networks: Ethereum, EOS, and Tron. We analyze security and privacy of the proposed system and evaluate how ensuring anonymity affects user experience. We conduct user-oriented test to explore the performance (transaction time and cost) of the system in realistic situations. Results indicate that the proposed concept is feasible while employing current blockchain technology. EOS and Tron implementations currently provide performance that matches existing centralized systems. The performance of Ethereum implementation would probably not meet user expectations.