PLVSNs: A Privacy-Preserving Location-Sharing System for Vehicular Social Networks

Combining Vehicular Ad Hoc Networks (VANET) and mobile online social networks (mOSNs), Vehicular Social Networks (VSNs) can provide more complex and rich services, including location sharing services, which brings more convenient communication and information sharing. However, location sharing in VSNs demands advanced privacy-preserving schemes to protect vehicles' social relationships and location information. Previous solutions employ Location Based Server (LBS) to manage users' location information. However, the server may collect the messages it has received to get more information of vehicles. Moreover, the threshold distances privacy is not properly protected, which may disclose users' identities. In order to overcome the shortage, we propose PLVSNs, a privacy-enhanced location-sharing scheme in VSNs. It takes advantage of vehicles' increasingly superior computing power, allowing vehicles and SNS to implement the distance comparison without LBS. Furthermore, we introduce a privacy enhanced distance comparison protocol, which provides a more efficient comparison between the actual distance and the threshold distance while not disclosing vehicles' privacy. We also show that the new construction is secure. Finally, we implement PLVSNs and the experimental results demonstrate the efficiency of our proposed scheme.