Survey on VANET Protocols and Security Techniques

Recently, vehicular ad hoc network (VANET) becomes increasingly popular in many countries. It is an important element of the Intelligent Transportation Systems (ITS). In a typical VANET, each vehicle is assumed to have an on- board unit (OBU) and there are road-side units (RSU) installed along the roads. A trusted authority (TA), a server is installed in the back end. The OBUs and RSUs communicate using the Dedicated Short Range Communications (DSRC) protocol over the wireless channel while the RSUs, TA, and the application servers communicate using a secure fixed network (e. g. , the Internet). The basic functionality of a VANET is to allow arbitrary vehicles to broadcast safety messages (e. g. , vehicle speed, turning direction, traffic accident information) to other nearby vehicles (denoted as vehicle-vehicle or V2V communications) and to RSU (denoted as vehicle-infrastructure or V2I communications) regularly such that other vehicles may adjust their traveling routes and RSUs may inform the traffic control center to adjust traffic lights for avoiding possible traffic congestion. As such, a VANET can also be interpreted as a sensor network because the traffic control center or some other central servers can collect lots of useful information about road conditions from vehicles. It is natural to investigate how to utilize the collected real-time road conditions to provide useful applications. In this study, proposed application VANET- based secure and privacy-preserving navigation (VSPN), which makes use of the collected data to provide navigation service to users. Based on the destination and the current location of the driver (the query), the system can automatically search for a route that yields minimum traveling delay using the online information of the road condition. In addition of driving guidance, the navigation results can also be used for other purposes like sharing images and videos.