Research And Implementation Of Privacy-Preserving Traffic Flow Analysis Scheme For Intelligent Transportation System

With the rapid development of Internet technology and social economy, people's living level also gets obvious improvement, the average number of vehicles in family has increased year by year, and the demand for transportation of people also has no decreasing trend. Although it facilitates people's daily life and promotes the national economy development, it has also brought enormous pressure to urban road traffic. To alleviate this situation, Intelligent Transportation System(ITS) has developed rapidly, and caused the research upsurge of academia and industry in recent years. And with the pervasiveness and development of ITS, Vehicle Information System(VIS) and Vehicle ad-hoc network(VANET) and other emerging intelligent transportation technology has been developed. Intelligent Transportation System(ITS), which can improve road traffic and reduce the number of traffic accidents, has attracted considerable interest recently. However, the flourish of ITS still faces many challenges including the privacy of individual data and locations, such as a single user data privacy protection and location privacy protection problems. The existing schemes can solve the problem of privacy protection to some extent, but they are poor-precision and not security. In this paper, according to the challenge of the intelligent transportation system faced, by analyzing the characteristics of the existing scheme, we focus on single user's data and identity privacy-preserving in intelligent transportation system based on the homomorphic Paillier cryptosystem. Specific work content is as follows:Firstly, by analyzing the existing schemes, we map the road information to a super-increasing sequence, and aggregate the multidimensional data to the one-dimensional data, which not only reduces the intermediate node' load but also improve the transmission and processing efficiency in intelligent transportation system. At the same time, the using of super increasing sequence, make the traffic management center distinguish between the information of each section clearly, and realize the fine-grained traffic flow collection and analysis.Secondly, using polymerization technology, Paillier homomorphic encryption technology, and the BLS short signature technology, we realized the goal of calculating and analyzing the average speed and the number of users in each section under the premise of userprivacy-preserving. It can benefits the travel of people and realize the user's data privacy protection in high precision.Thirdly, avoid the risk of leaking identity privacy of user to intermediate nodes. Each legitimate user collecting speed information real-time, and send it to the Road Side Unit(RSU) which he(her) belongs after encrypting and make signature in the vehicle terminal device. After receiving the data, the RSU can't decrypt the cipher text. So it sent the preliminary polymerization data to the traffic management center after making a signature directly. Therefore, in the whole process, the user's identity will not be revealed to the road side unit. And the information of single user is security, we achieve the privacy-preserving of single user's data.