The Security Strategy In Wireless Sensor Network Based On Reversible Digital Watermarking

With the deep-research of embedded technologies and microelectronics, Wireless sensor networks (WSNs) have great potential in practical application, especially in the military, medical, the public safety and so on. The sensor nodes are deployed in the unattended monitoring area, collecting the real-time monitoring data for the analysis of the situation. Wireless sensor networks are data-centric. How to make effective measures to implement data security issues of networks is still an unsolved problem. 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 sensor data.Arming at the features of WSNs and the lack of existing technologies, combining the security control to watermarking technology, we are trying to solve the security problem such as data integrity protection and copyright protection in the whole course of data acquiring, transmitting and application in WSNs.The main contribution of the study was as follows:(1) We proposed a novel data integrity protection strategy based on reversible and fragile digital watermarking scheme. The source sensors use a one-way hash function for collecting data to generate watermark information. Then the watermark is embedded into the difference of the adjacent data according to the reversible algorithm by using the correlation among the neighbor data. The method has small effect on the embedded data and observer can scarcely detect the change. After receiving data, the sink node restores the original data and verifies the reliability. The real experiments also demonstrate that our algorithm can losslessly authenticate sensor data with low energy overhead and have more application values.(2) Besides detecting the integrity of sensor data, we also need to take consider of the copyright protection. We proposed a multi-mark chaining watermark to protect the integrity and the copyright. Our scheme is improved on the basis of traditional chaining watermark. The watermark contains of an annotation part and a fragile part. The dynamic grouping firstly divides data into two parts. On the one hand, the fragile watermark is embedded into the first part to verify the integrity. On the other hand, the annotation watermark is embedded into the second part to validate the protection while keeping the sender and the receiver synchronized as group delimiters. The both two kinds of watermark are lossless and the accuracy of data before and after transmission is not affected. The real experiments and analysis also show that our scheme can not only detect the integrity but protect the copyright effectively.