Providing security in Vehicular ad hoc networks (VANETs) through historical data collection

Today Vehicular Ad-hoc Networks (VANETs) are needful to improve safety on the roads. But using this kind of networks has a few issues. Providing security is one of the most important issues that users of VANETs are associated with. Our purpose of security is the reliability of information. Security is lost when a user or group of users try to send invalid information into the network for their individual purposes. The approach presented in this paper works by the following assumption. One of them is, a unique identifier (called ID) is assigned to each vehicle, and all the communicated messages contain this ID. The approach works by keeping the history of reported messages. By using probabilistic roles, we show that in an unsecure/secure environment how many reports is necessary to rely on a report (message). This reliability helps the driver in making true decisions when he has no information about the message trueness. E.g., message contains the information that an incident (collision, accident and etc) has occurred in a specific place on your way. You may change your way. But you need to ensure the message is true. Our proposed approach is based on this fact that how more an incident is reported it has more probability to be true. In the cases that message validity is not guarantied driver is responsible for trust to received information. At the end, some diagrams show, in different environment, how many reports should be received to rely on a specific report. KeywordsVANETs; Security; decision making; Introduction VANET was created in October 2002 by the (FCC). The aim of its creation was to improve safety on the roads. A vehicular ad hoc network is also known as a vehicular sensor network by which driving safety is enhanced through inter-vehicle communications or communications with roadside infrastructure. It is an important element of the intelligent Transportation Systems (ITSs). In a typical VANET, each vehicle is assumed to have an on-board unit (OBU) and there is road-side units (RSU) installed along the roads. A trusted authority (TA) and maybe some other application servers are installed in the backend. 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 function of a VANET is to allow arbitrary vehicles to broadcast safety messages (e.g. road condition, traffic accident information) to other nearby vehicles and RSU such that Dr.Kamal Jamshidi et al. / International Journal on Computer Science and Engineering (IJCSE) ISSN : 0975-3397 Vol. 3 No. 4 Apr 2011 1393 other vehicles may adjust their travelling routes and RSU may inform the traffic control center to adjust traffic lights for avoiding possible traffic congestion. [15]