Low-power Data Protection for Energy-harvesting Beat Sensors

Beat sensors are novel power-harvested devices with ultra-low-power sensing mechanisms that can collect data and send it using LoRa using millijoules of energy. Instead of reading the sensor values using ADC, beat sensors are carefully designed to sense the data and encode the values in the interval times of data transmission. However, no security mechanisms have been integrated to protect the collected data because of the limited power supply. In this paper, we will analyze the security problems in beat sensors and propose lightweight data protection mechanisms while considering the power budget. The proposed data protection method has been implemented in software on an STM32 controller using True Random Number Generators and lightweight blockcipher Simon and Speck, and it has been tested in the Beat Sensor system.