Towards Privacy in Geographic Message Dissemination for Connected Vehicles With geographic message dissemination, connected vehicles can be served with traffic information in their proximity, thereby positively impacting road safety, traffic management, or routing. Since such messages are typically relevant in a small geographic area, servers only distribute messages to affected vehicles for efficiency reasons. One main challenge is to maintain scalability of the server infrastructure when collecting location updates from vehicles and determining the relevant group of vehicles when messages are distributed to a geographic relevance area, while at the same time respecting the individual useru0027s privacy in accordance with legal regulations. In this paper, we present a framework for geographic message dissemination following the privacybydesign and privacybydefault principles, without having to accept efficiency drawbacks compared to conventional serverclient based approaches.

SmartphoneBased Platform for Secure MultiHop Message Dissemination in VANETs Vehicular adhoc Networks (VANETs) are recognized as a cornerstone of Intelligent Transportation Systems (ITS) to enable the exchange of information among vehicles, which is crucial for the provision of safetyrelated and entertainment applications. However, practical useful realizations of VANETs are still missing, mainly because of the elevated costs and the lack of a final standardization. In this regard, the feasibility of using smartphones as nodes in VANETs has been explored focusing on smallscale deployments to mainly validate singlehop communication capabilities. Moreover, existing smartphonebased platforms do not consider two crucial requirements in VANETs, namely, multihop communication and the provision of security services in the message dissemination process. Furthermore, the problem of securing message dissemination in VANETs is generally analyzed through simulation tools, while performance evaluations on smart devices have not been reported so far. In this paper, we aim to fill this void by designing a fully ondevice platform for secure multihop message dissemination. We address the multihop nature of message dissemination in VANETs by integrating a locationbased protocol that enables the selection of relay nodes and retransmissions criteria. As a main distinction, the platform incorporates a novel certificateless cryptographic scheme for ensuring data integrity and nodesxe2x80x99 authentication, suitable for VANETs lacking of infrastructure.