PROS: A privacy-preserving route-sharing service via vehicular fog computing

In vehicular networks, route sharing is a novel cloud-computing service, where users form groups with their friends, set up a common destination, and share real-time locations and routes. However, to form these groups, users have to upload their group formation or participation requests to a remote service provider that consumes a significant amount of network bandwidths and incurs an increase in the response delay. Meanwhile, users' sensitive information, such as identity and location, along with their group privacy, such as social graphs are entirely exposed to the service provider, thereby causing critical user privacy threats. Herein, we first introduce fog computing into a route-sharing service model in vehicular networks, where fog nodes preprocess user data. Second, group privacy is defined and three new attacks are considered, namely, member impersonation attack, group affiliation attack, and unlimited participation attack, under this model. Third, the privacy-preserving route-sharing (PROS) scheme is proposed to protect user and group privacy by utilizing improved anonymous authentication, rate limiting pseudonyms, modified privacy-preserving equality test, and location geo-indistinguishability. Finally, the security and privacy of the PROS scheme is analyzed and extensive experiments are conducted to compare its efficiency with existing schemes.