Research On Detecting And Defending Of Sybil Attack In Wireless Sensor Networks

With the rapid development of wireless communication and sensor technique, Wireless Sensor Network (WSN) is stepping from research into practice. For its bright future in the area of military, scientific and commercial application, WSN has become a hot point that attracts the attention from academe and industry. Wireless sensor network is commonly deployed in harsh, unattended or even hostile environment. Due to the limited resources and power of sensor nodes, security of WSN is becoming the key problem of research area.Sybil attack is a harmful threat to wireless sensor networks. In Sybil attack, a malicious node behaves as if it were a large number of nodes, for example by impersonating other nodes or simply by claiming false identities. Addressing this problem, we present two solutions to detect and defend Sybil attacks in wireless sensor networks: an Received Signal Strength Indicator(RSSI) based detecting mechanism; a Cluster-based Merkle hash tree Defending Mechanism (CMDM) .In the first solution, we improved and implemented use more than one node to receive the values of RSSI from the sender, and then detect the Sybil attacks in wireless sensor networks with the collaboration of all the receivers. The solution avoids the need for public key cryptography, so it is able to control the energy consumption effectively and save the memory space as much as possible in the process of detecting Sybil attacks. The RSSI based Sybil attack detecting mechanism is acceptable in the wireless sensor networks.In the second solution, for the purpose of verifying the identity of the new node that is coming into one cluster and ensuring the secure communication between nodes, we use the nodes in that cluster to sustain a Merkle hash tree. The solution belongs to simple symmetric encryption techniques, and avoids public key cryptography, so its overhead (computation, storage) is acceptable, and it is scaleable in the large-scale distributed wireless sensor networks.Two solutions have been verified through theoretical and experimental analysis, and are proved to work well for the Sybil attack detecting and defending in wireless sensor networks.