Low-Power AES Data Encryption Architecture for a LoRaWAN

In recent years, the Internet of Things (IoT) has significantly increased the number of Internet connections to a large number of objects in different domains, including industry, homes and transportation. The LoRaWAN developed by the LoRa Alliance is a long-range wide area network specification suitable for an IoT environment due to its low-power communication. It provides a star-of-stars topology, well-defined MAC layer protocol and three communication modes to further lower its power consumption and employs the Advanced Encryption Standard (AES) cryptography and several session keys to increase its network security. However, for battery powered IoT end nodes, the AES encryption process consumes some amounts of power owing to involving multiple cycles of repetition. To solve this problem, in this study, we propose a low power consumed AES encryption architecture, named Low-Power AES Data Encryption Architecture (LPADA), which reduces the power consumed by the AES for data encryption by using low power SBox, power gating technique and power management method. A key updating procedure is also proposed to increase the security of the session-key renewal. The system is simulated using the Synopsys library with five different supply voltages. The experimental results show that 62.0% of dynamic power reduction and 88.5% of leakage power lowering have been achieved compared to the power consumed by traditional AES data encryption. The security analysis also shows that the key updating procedure for the LPADA enables mutual authentication between end nodes and application servers, and resists replay attacks and eavesdropping attacks from hackers.