Power Consumption of Common Symmetric Encryption Algorithms on Low-Cost Microchips

In the Internet of Things (IoT), many devices are battery-operated, making them particularly susceptible to power-hungry applications. Symmetric encryption is a regularly performed task on such devices, as it ensures the confidentiality of the data they send. While previous work has compared the power consumption of common symmetric encryption algorithms on commodity hardware, no such evaluation exists for low-cost microchips, which are often used in IoT devices. In this paper, we compare the power consumption of an ESP8266 executing common symmetric encryption algorithms with varying parameters such as key size, data authentication, or payload size. We find that the power consumption depends on several factors, but that overall AES-GCM has the lowest power consumption when the encrypted data is also authenticated, while Blowfish-CTR has the lowest power consumption when no authentication is applied.