Improving the Physical Layer Security of the Internet of Things (IoT)

The Internet of Things (IoT) is one of the most promising technological revolutions. However, the IoT is inherently vulnerable to attacks. In this paper, we propose to enhance the physical layer security of the IoT by using a technique called information passing and interference addition. In the physical layer security analysis, the achieved secrecy rate has an inverse relationship with the intruder’s distance to the legitimate transmitter. The aim of our work is, first to increase the achievable secrecy rate by letting the legitimate transmitter find an alternative route to the fusion center to achieve a higher secrecy rate than the direct route. Hence, the legitimate transmitter must not disclose the actual information to the fusion center if there is an eavesdropper located between them, instead, it must pass the information to another node via a directional antenna to concentrate the power towards the intended receiving node. Passing the information to the nearest node must be done under the condition that there is no intruder in between. Second, we used simultaneous multi-stream beamforming transmission to strengthen the legitimate receiver’s signal-to-noise ratios and at the same time, it poisons the eavesdropper channel with interference. Third, the proposed node may disclose a false information to the intruder in some cases. The system has been designed and the secrecy analysis of the system has been investigated. The result showed that using directional antennas would increase the probability of having at least one secure connection coming out of the node to the other legitimate nodes by 30% than the omni antenna. Moreover, the results showed that using the simultaneous multi-stream beamforming would improve the legitimate channel’s achievable secrecy rate and that it has superiority over the directional antenna effect.