Security And Broadcast Authentication In Wireless Sensor Network

Wireless sensor networks (WSN), integrating sensor technology, embedded computation technology, wireless communication technology and etc., is a novel information acquiring and processing system, and can be widely applied in many fields, e.g. national defense and military, environment monitoring, traffic management and medical health. Because of open deployment area and broadcast characteristic of wireless network, WSN is susceptible to be eavesdropped and maliciously attacked, and thus the security problem becomes essential. And, broadcasting is an important communication type in WSN, but there is lack of effective solution to secure broadcasting at present. Secure broadcast communication becomes the most prominent security problem in WSN.The thesis thoroughly analyzes security of WSN, and mainly focuses on secure broadcasting. After analyzing and discussing proposed broadcast authentication schemes, the thesis proposes a novel hierarchical authentication scheme for secure broadcasting based on clustering. This scheme employs a 2-tier hierarchy, here the base station distributes key-pool for every cluster with clustering information which is gained by routing protocol. And then each cluster head distributes key-rings for in-cluster nodes, authenticates broadcast packets by using shared keys between its local key-pool and base station's authenticating keys, and thus assists in broadcasting within cluster. Clustering structure of sensor nodes can effectively prevent broadcast storm and reduce network energy consumption, and can support hierarchical authentication so as to deter middle nodes forwarding error information. This scheme employs the one-authenticator-for-one-message mechanism to ensure individual and timely authentication, and one-bit authentication mechanism to reduce the communication overhead. The result of theoretical analysis and simulation proves that this scheme improves greatly the performance of broadcast authentication in some aspects, e.g. security, scalability, real-time authentication and resistibility to specific attack, and is more suitable for broadcast authentication in large scale and non-periodic communication of WSN.