Research On Streaming Data Security Of Wireless Sensor Network

Wireless sensor networks (WSNs) have great potential in embedded technologies and microelectronics. The security of WSNs has become the major concern of many researchers. It is a key issue for protecting the whole process of streaming data flowing, especially in data-centric WSNs. The traditional strategies are difficultly applied into WSNs because of the limitation of computation and resource. Some new security mechanisms are urgently required for comprehensive protecting to the streaming data.Aiming at the features of WSNs and the lack of existing technologies, combining the security control to streaming data and IH technology, taking the data flowing as the main line, we are trying to solve the security problem in the whole course of data acquiring, transmitting and application in WSNs. The trusted data source, controlled data transmission and reliable data application, are interpenetrating and closed connection, which are directly affecting the network security and the obtained data. The main works are as follows.(1) For the data source security, it is possible to face different security threat that is difficult to forecast.â‘ For ensuring the authenticity of data sources, we propose a Creditable Source Filtering Mechanism (CSFM). The sensor embeds the identity into data before sending, and the immediate node validates the consistency of mark. It will transmit the data to the next when it passed the validation, otherwise to terminate the communication for filtering the suspicious data. We can obtain the goal of saving consumption and filtering the fake data by using CSFM, which is avoid of disturbing the sensing results and ensures the authentic data sources.â‘¡In order to hide the mark into data, we propose a Manchester-code-based Streaming Hiding Algorithm (MSHA). We embed the mark by changing the switching state of some bits of data. The hidden mark has good invisibility and does not occupy the extra space in packets. Furthermore, we develop the fragile MSHA and high capacity MSHA in cope with slight data changed and long mark embedded, which is for danger application and big size network respectively. The simulation result show that MSHA can hide the identity of node well invisible, CSFM ensures the credible data source by validating the authentic and the integrity of data and filtering the invalid data.(2) For the data transmission security, the data have the risks of being intercepted and tampered in the wireless communication, especially involving with some sensitive or secret content in national defense and military applications. Traditional cryptography solutions are difficult to practice for much faultiness such as high computation cost and huge key management.â‘ To ensure that the obtained secret-associated information can be transported to Sink safely, we design a secure data transmission strategy based on IH to utilize the monitored channel for secret transmitting. Additionally, we propose a High Capacity Hiding Algorithm (HCHA) for enormous data embedding. HCHA enlarges the embedding position within the accepted range of data, which sacrifices data precision for more information hidden. The simulation results demonstrate that HCHA has the tradeoff between the capacity and the invisibility. It has good capacity while reduce the energy consumption for sensitive data transmitting covertly.â‘¡To avoid more damage into WSNs, we study the problem of adversaries detecting and isolating based on the mobile sensor. Firstly, we propose the Minimal Damage Coverage Traversing (MDCT) problem. Then, Weighted and Hierarchical Isolating Adversaries (WHIA) algorithm is designed and implemented. The mobile sensor makes decision by weighing both the significance and the priority of nodes level by level while only use local position message. It will cut them for communication from the trusted nodes when finding malicious nodes. The simulation results show that WHIA can isolate malicious node, alleviate the damages of network, and hence increase the robustness of WSNs against adversaries.(3) For the data application security, there is a problem that cryptography is high computation cost and the decrypted data are difficulty to control. We study the streaming watermarking algorithm for copyright protection and traitor tracing aiming at the threat of streaming data misuse, unauthorized spread and illegal copy.â‘ In order to increasing the invisibility of watermarking, we propose a Virtual Grouping-based Watermarking Algorithm (VGWA). VGWA first constructs the virtual residual group by constructing a complete residual system. Then it embeds one bit in each group by setting a random number to a specific position according to the second-LSB of data instead of embedding directly. The mark is retrieved in groups by comparing with the threshold, which is set according to the distribution probabilities of data, with the maximum occurrence frequency of the data in the corresponding position in extraction. The simulation results show that the algorithm has a well invisibility and a good robustness while it embeds the mark evenly.â‘¡For the requirement of some high data precision applications, we propose a Lossless Streaming Watermarking Algorithm (LSWA). The mark is embedded into streaming data without modifying the value. Through adjusting the sequence of data in every packet and keeping the value of the data unchanged, we embed the watermark into the streaming data. Then we design online extraction for authenticity validating and off-line detection for copyright proofing to the segment of data. The experiment results demonstrate that LSWA has good efficiency.â‘¢To solve the problem of the missed data when transmitting and the malicious deleted the data, we further propose a Fountain Code-based Streaming Watermarking (FCSW). Utilizing the anti-erasure feature of Fountain Code, we encode the mark before embedded for increasing robustness. Then we design the modified Raptor code (MRC) to steady the performance of anti-erasure. We also extract the hiding mark even that there are data losed when we obtain a certain number of codes. The simulation results show that MRC code has equable anti-erasure performance and FCSW is robust to data losing and deleting.In summary, we present solutions to several key problems of data security in data acquiring, transmitting and application. Aiming at different application scenario, we propose a reasonable and effective solution, which has theoretical and practical value for advancing the theory and practicability of reliable data transmission in wireless sensor networks.