Developing preventive mesurements against attacks on wireless networks

Wireless Sensor Networks (WSN) and Ad Hoc networks are being using in different applications and fields of our life in the modern era. They are used in the military, medical, industrial, disaster relief, and commercial applıcatıons. Security is an important challenge in the wireless networks. Most of the wireless networks are susceptible to different attacks. In this study we address Sybil attack which uses multiple identities for a node to create the illusion that these identities come from multiple nodes. In this thesis, we propose a method to detect and prevent Sybil attacks. In our method, we consider WSN application in vehicular networks (VANET) where we detect Sybil attack without knowing the identity of the malicious node which preserves the user privacy as well. The proposed method is simulated in NS2, a widely used open source network simulator. The results are compared with the realistic test case conducted by the centralized authority DMV in terms of the detection rate and overheads.