Neighbor risk reporting in vehicular networks

With the issuance of the Notice of Proposed Rule Making (NPRM) for Vehicle to Vehicle (V2V) communications by the United States National Highway Traffic Safety Administration (NHTSA), the goal of the widespread deployment of vehicular communications and networking has taken a significant step towards becoming a reality. As with most connected technologies, protection of privacy is an ongoing concern. In order for consumers to accept the technology, it is expected that reasonable mechanisms will be in place to protect their privacy. Cooperative Caching has been proposed as an approach that can be used to improve privacy by distributing and caching data items throughout the mobile network as they are requested. When a device requires a data item, it will first query other devices for the data item before querying a centralized server. The privacy improvement is achieved by alleviating the need to send all requests to a centralized location that may be vulnerable to an attack. However, with this approach, the requesting device exposes itself to one or more generally unknown devices in the network as part of the data discovery process. This presents another privacy concern in the sense that these devices may expose information related to the request. In this paper we present a novel Cooperative Caching system in support of non-safety based applications (such as the many location based services) in which devices monitor the relative risk associated with each of its neighbors. Based on this information, requesting devices select and query specific neighbors that present little risk while avoiding neighbors that might present higher risk. We have conducted a preliminary performance evaluation of our approach that demonstrates a significant reduction in the overall risk of exposure when compared with simply broadcasting the request to all neighbors.