Towards More Scalable and Secure LPWAN Networks Using Cryptographic Frequency Hopping

Abstract

The Internet of Things (IoT) vision has recently given rise to low-power wide area networks(LP-WAN) which offer multi-km communication range. Ericsson and Cisco Internet Business Solutions Group (IBSG) predict that by 2025, more than 50 billion devices will be connected through LPWAN technologies to collect real world data [1]. LoRaWAN is being deployed by many countries around the globe and gaining rapid acceptance and popularity in the LPWAN space. LoRa technology has enabled a new type of low data-rate services that are suitable for wide geographical areas with several years of battery life. However, the technology has limitations that need to be addressed. The high-density development of end devices transmitting using uncoordinated messaging makes the network more vulnerable to selective jamming and network contention. This paper proposes a solution to mitigate these effects through secure random frequency selection on end devices(i.e. cryptographic frequency hopping). In particular, proper time, spreading factor (SF) and frequency selection may allow multiple unconfirmed communications to occur concurrently while minimizing opportunities for contention and jamming. This was done by implementing cryptographic frequency hopping technique to select N-possible number of evenly optimized channels from available frequency spectrum (EU863-870MHz). The results were implemented and evaluated using commodity hardware.