OTA Firmware Updates for LoRaWAN Using Blockchain

LoRa WAn is one of the LPWAN technologies that has become popular in both industries and research. LoRaWAN aims to provide long-range communication and empowers low-powered devices to last for years in the field. LoRaWAN relies on the symmetric cryptography to provide end-to-end encryption. Even though LoRaWAN relies on symmetric cryptography, there are recent works that try to enhance security of LoRaWAN by incorporating technologies like Blockchain. Blockchain is a decentralized peer-to-peer network that provides tamperproof and immutability of data. This paper proposes a Blockchain-based firmware update mechanism to enhance firmware update in LoRaWAN as well as managing the update process. This mechanism aims to provide updates by ensuring authenticity, and integrity of the firmware. The mechanism focuses more on devices that are too constrained in resources, hence for that purpose we evaluated the cost involved in some cryptographic operations taken to ensure security during firmware updates. We conclude that the approach is feasible for constrained devices in LoRaWAN network by evaluating the memory usage of the cryptographic operation used by the end device.