This book is written to explain the concept of VANETs, its different characteristics and the challenges it faces in the light of network security. The security and privacy concerns of VANETs are highlighted and also different attacks and the proposed solutions are given for implementation. The concept of cryptography and different encryption algorithms used for providing security to the data are brought into concern of the reader. The different authentication schemes based on cryptography and signature are explained in detail. The shortcomings of these schemes are also picked up and presented to the readers. The concept of certificateless schemes and their aggregate verification process (CLAS) is explained to the users and difference between other schemes and CLAS is also picked up. In the end different applications and future scope of VANETs is explained.