The IoT (Internet of Things) knows a great expansion with a predicted of 75 billions of IoT devices by 2025 [Cisco]. LPWAN have emerged as one of the most promising IoT wireless technologies. They are appropriate for devices that require small amounts of data over a long-range, at a low cost, while maintaining long battery life. As for any communication systems, security is one of the biggest concerns. In LPWAN, security is currently provided by symmetric-key algorithms such as AES-128 at upper levels. In the case of LoRaWAN, it offers application-level payload encryption and network-level integrity. Nevertheless, this does not shield it against attacks at a lower level such as jammer-type attacks. A jamming attack takes place at the PHY la...