            ! " #"#$ %%#  &  ’’’( © 2010, IJARCS All Rights Reserved 595 ISSN No. 0976-5697 A Novel Approach for Providing Security in Vehicular Adhoc Network Through Vehicles Present in the Network Vijayan.R Assistant Professor (senior grade) School of Information Technology and Engineering VIT University, Vellore, India vijayan_ram@yahoo.com Sumitkumar Singh* Master of Technology School of Information Technology and Engineering VIT University, Vellore, India research.sumit@yahoo.com Abstract: Infrastructure based Vehicular ad hoc network has indeed increased the efficiency and accuracy of the network but at the same time it has also increased the cost required for the setup of such network. Therefore there exist needs wherein the nodes within the network itself provide security features hence eliminating the need for setting up of an expensive network. In this paper we have proposed a novel approach wherein the nodes itself can act as a central authority which will provide requesting nodes with public and private key. To improve the performance and at the same time to enhance the security and to provide confidentiality and integrity we have proposed the use of Signcryption [1, 2]. In order to take the performance of the network to next level we have proposed the use of improved Signcryption [2]. Providing improved Signcryption through nodes present within the network are the main focus of this paper. Keywords: Signcryption, Current Coverage Area (CCA), CA node, Single hop Transmission, Multi hop transmission I. INTRODUCTION Security in Vehicular ad hoc network has always been the major research area. Infrastructure based network has indeed helped in increasing the security levels in VANET but meanwhile it has also led to some major drawbacks which include the cost involved for the setup of such network. Setting up of an infrastructure based network requires the services of Roadside units which act as an access point in the network. [4] Describes the usage of RSU and has been termed as Service Units (SU). These RSU can act as an access point or certificate granting authority or may be programmed for other relevant usage. These RSU are connected to a server which provides relevant features to the nodes present within the network. Such network becomes a very effective network but it increases the overall deploying cost. Therefore to reduce such drawbacks of the system a novel approach has been proposed wherein the security features will be provided by the node itself present within the system. Such nodes are considered as the trusted nodes which can be a government vehicle e.g. police vehicle, Government ambulance or vehicles assigned by the service providers .VANET suffers from many limitations which include availability of limited resource, frequent path breakage due to its dynamic nature. In such network it is required that the computation cost involved in the system should be less. In order to achieve such goals we have proposed the use of Signcryption [1]. Signcryption combines Digital signature and Encryption in logically single step unlike Digital signature than encryption which requires more machine cycle for processing than Signcryption. [3] Describes an approach wherein digital signatures are used in automobiles. The proposed model in [3] is effective but suffers from additional computational cost. A more enhanced feature has been proposed in [2] which have modified Signcryption to make it easier for computation. This paper has proposed the use of such [2] model which would help decreasing the computation cost and increase the performance level of VANET. II. NETWORK MODEL A. CA Node Central authority (CA) nodes are responsible for assigning public and private keys to the requesting nodes in the network. These nodes are assigned by the service provider based on their type i.e. a CA node can be a government vehicle like police cars, ambulance or some private vehicle designated by the service provider itself. The fig 1. Shows a typical network model proposed in this paper. B. Source Nodes These are the nodes which requests available CA node for transmission with the destination node. Figure: 1