Abstract: Vehicular Ad-hoc networks (VANETs) are very likely to be deployed in the coming years because of the safety requirements and thus become the most relevant form of mobile ad hoc networks. Security is the main issue in VANETs because of the main use of the VANETs is for safety related application and in that case the viability of the security may cause harm to human lives. In this paper, we address the security issues of this networks and the methods are used to solve the security issues and its consecuses overhead in VANETs.