Research On Security Policy In Wireless Sensor Networks Based On Digital Watermarking Technology

In the wireless sensor networks (WSNs), there are many security issues in the practical applications due to the limited ability of the node and the openness of the environment. Meanwhile digital watermarking technology as an important branch of the information hiding technology can effectively ensure the integrity and authenticity of the information. Therefore in this thesis we consider the security features of WSNs and use the digital watermark technology to solve two common security issues exist in the WSNs, the mainly work of this thesis is as follows:1) It proposes a selective forwarding attacks detection method based on the digital watermarking technology. This way introduces the watermarking, safety value and other factors to ensure the base stations (BS) can get the data safety. The sender embeds the watermark into the data which then is forwarded to the base station through the forwarding node, then the BS extract the watermark information and determine the integrity of the data. Once the BS judges there selective forwarding attack exists, it can find the malicious node, reduce the value of safety. This is to effectively ensure the safety of the data to avoid malicious nodes, select the node with higher safety value to be the forwarding node, and also can effectively avoid the error due to the BS make a mistake to judge a normal node as a malicious node. The simulation experiments tell us that: the method has a high level of detection efficiency in the different environments and attacks.2) It proposes an identification method using the digital watermarking technology to resolve the false data injection attack in the wireless sensor network. In the method, the nodes which have involved collecting the data in the cluster send the data authentication as the witness information, and this witness information will became the watermark embedding into the data. Ultimately the BS extracts the watermark from the data and determines the authenticity of data. Meanwhile through modify the existing reversible watermarking algorithm, proposes a reversible watermark algorithm while is suitable for the wireless sensor network. The Experiment tells us that in the presence of degree of noise, the information and watermark have a higher recovery rate. In the different network environments, the detection of false data packet and the duplicate data packets are maintained at a higher level.