“…One key feature of IoT systems is their ability to support a variety of legacy and emerging communication protocols, including SigFox, cellular technology, 6LoWPAN (IPv6 Low-power Wireless Personal Area Networks (LoWPAN)), BLE (Bluetooth low energy), ZigBee, RFID (radio frequency identification), NFC (near-field communication), Z-Wave, NB-IoT (Narrow Band IoT), LoRaWAN (long-range wide area network), and Wi-SUN (wireless smart utility network) [41]. There are currently eight major categories of PLS schemes that concentrate on data confidentiality for OFDM systems: channel-based encryption [42], phase encryption [43], permutation [44,45], artificial noise (AN) and artificial fast fading (AFF) [46,47], preamble modulation [48] (Figure 1), power allocation [49], Peak-to-Average Power Reduction (PAPR) encryption [50], the frequency domain [51] and the time domain [52] are two other areas in which these techniques can be used. Chaos-based physical layer encryption is used in OFDM-based IoT systems to achieve the phase randomization and constellation rotation in the transmitted image in both spatial and transformation domains.…”