Physical Layer Security for IoT Communications - A Survey

As the Internet of Things (IoT) grows, the number of resource-constrained devices also grows. The limitations of these devices impedes the usage of conventional security methods. However, physical layer security (PLS) has many diverse techniques that do not require significant resources that can be used to bolster the defenses of these devices. Due to the heterogeneity in IoT, we first consider relevant IoT communication protocols that are being used (WiFi, ZigBee, LoRaWAN) to connect these devices, and then the scope of surveyed PLS techniques is narrowed-down to a set of promising techniques that can be applied with the communication protocol. In this paper we explore recent developments in PLS techniques that require minimal to no overhead in their implementation, and provide security against some of the attacks that IoT devices and networks are vulnerable against: spoofing, jamming and eavesdropping attacks. The solutions explored include radio frequency (RF) fingerprinting, spread spectrum coding, and beamforming.