关键词: 高速公路, 自由流收费, 隐私保护, 区块链, 零知识证明

Abstract: In response to the issues of vehicle toll evasion caused by license plate cloning and potential user privacy leaks due to centralized data storage in the current intelligent transportation highway free-flow tolling schemes, a blockchain and zero-knowledge proof-based free-flow tolling method for highways was developed. Initially, a video surveillance mechanism for toll evasion detection was designed to ensure the compliance of vehicles on highways. Subsequently, smart contracts within the blockchain were designed to encrypt and store vehicle location certificates and payment data in a distributed ledger. Zero-knowledge proof technology was introduced to ensure the correctness of payments while protecting privacy, and an algorithm for charging tolls based on the vehicle's mileage was designed within the zero-knowledge circuit. Theoretical analysis and simulation experiments demonstrated that under normal conditions, the method achieves accurate toll collection based on the actual driving mileage with zero-knowledge of location privacy, and in the event of exceptions, it can provide timely warnings and record anomalies on the blockchain. The average toll collection time has been reduced from 38 seconds to 1.8 seconds, a decrease of about 0.1 seconds compared to the methods combining 5G and Electronic Toll Collection (ETC). For the same entry and exit points, the lower the overlap in the number of Information Collection Point (ICP) on different routes, the more accurate the mileage-based tolling.

Key words: highway, free-flow tolling, privacy protection, blockchain, zero-knowledge proof