Towards A Scalable and Privacy-Preserving Blockchain-based European Parking System

The importance of efficient and accessible parking systems has been growing over the past decades. Steady growth in urban population and car ownership has increased problems with traffic congestion and air pollution caused by inadequate parking systems. Blockchain-based parking systems have been proposed to increase system availability and resilience and improve trust among participants. However, these systems are not transferable to the parking systems of European cities such as Copenhagen, as they are based on assumptions about the parking infrastructure, which do not hold, and are inherently incompatible with regional privacy protection regulations such as the GDPR. Furthermore, many blockchain solutions suffer from scalability issues, severely limiting their efficiency. In this work, we develop a blockchainbased parking system in Denmark, aiming to make up the gap in the existing research by directly considering GDPR compliance. Our work focuses on the municipal parking system for on-street parking in Copenhagen (Denmark), where Hyperledger Fabric is used to maintain a trusted distributed ledger for parking data shared by the network. Personal data is protected through offchain storage while maintaining on-chain verifiability. The proposed system is implemented as a proof-of-concept application, which can deliver sufficient throughput to support the needs of municipal parking.