Physical layer secrecy solution for passive wireless sensor networks

The backscatter communication system has tremendous potential in commercial applications, still very less work has been done to study the benefits of it. Backscatter communication system is the backbone of many low cost and low power distributed wireless systems. The data transmission between various nodes in wireless communication system always comes with the risk of third party interception. This leads to privacy and security breaches of the information. In this paper, physical layer security of backscatter wireless system for multiple eavesdropper, single tag, and single reader case is studied. Unique characteristics of the channel are used to provide security to signal transmission. In order to degrade the reception of the signal by eavesdropper, a noise injection scheme is proposed. The advantages of this approach are discussed for various cases while evaluating the impact of the key factors like antenna gain and location of the eavesdropper on the secrecy of the transmission. Analytical results indicate that if properly employed, the noise injection scheme improves the performance of backscatter wireless system.