PTFA: a secure and privacy-preserving traffic flow analysis scheme for intelligent transportation system
With the pervasiveness of vehicle information systems (VIS) and the advance of vehicular ad hoc networks (VANET), intelligent transportation systems (ITS), which can improve road traffic and reduce traffic accidents, have attracted considerable interest recently. However, the development of ITS still faces many challenges including privacy of individual data and locations. In this paper, we propose a secure and privacy-preserving traffic flow analysis scheme, called PTFA, for ITS. With PTFA, user privacy can be guaranteed when the manager acquires the fine-grained traffic information. We first map the information of roads to a super increasing sequence; then, construct an improved multi-dimensional aggregation scheme based on the homomorphic Paillier cryptosystem. For data communications from user to traffic regional-centre (TRC), data aggregation is performed directly on ciphertext at road side units (RSUs) without decryption, and the aggregation result of the original data can be obtained at the TRC. Detailed security analysis shows that the proposed PTFA scheme can efficiently achieve user privacy-preserving in ITS. In addition, performance evaluations via extensive simulations demonstrate the PTFA's effectiveness in terms of providing fine-grained traffic information processing and minimising communication cost.