Impact of Encryption Mechanisms on Power Consumption in LoRaWAN and NB-IoT Networks

Abstract

As the Internet of Things (IoT) expands rapidly, Low Power Wide Area Networks (LPWANs) like LoRa and NB-IoT have become essential for connecting devices with limited power. However, maintaining secure applications while minimizing power consumption is a significant challenge due to the trade-off between energy efficiency and data protection. This paper investigates the impact of implementing security mechanisms, specifically transmitted data encryption, on power consumption in LoRa and NB-IoT networks. The study highlights how various encryption schemes affect battery life, latency, and connection stability. Key findings demonstrate that while NB-IoT utilizes hardware-accelerated security via cellular modules for efficiency, LoRaWAN relies on software-based AES-128 encryption which increases CPU cycles and energy usage. Experimental results for LoRaWAN show that increasing the AES key size from 128-bit to 192-bit and 256-bit leads to a substantial rise in energy consumption and processing delays. Specifically, AES-256 increased energy consumption by 30–32% and processing time by up to 32% compared to the baseline. The study concludes that while security is vital, its implementation must be carefully planned to prevent drastically lowering energy efficiency in battery-powered IoT devices. It is recommended to use AES-128 for a balance of security and power, alongside power management modes like deep sleep to further extend battery life.