Part1: Low Powered and High Risk: Possible Attacks on LoRaWAN Devices
https://www.trendmicro.com/en_us/research/21/a/Low-Powered-but-High-Risk-Evaluating-Possible-Attacks-on-LoRaWAN-Devices.html

Part2: Gauging LoRaWAN Communication Security with LoraPWN
https://www.trendmicro.com/en_us/research/21/b/gauging-lorawan-communication-security-with-lorapwn.html

Part3: Protecting LoRaWAN Hardware from Attacks in the Wild
https://www.trendmicro.com/en_us/research/21/c/protecting-lorawan-hardware-from-attacks-in-the-wild.html

Thanks to TrendMicro & Sébastien Dudek for those excellent articles about LoRaWAN security