STIR: A Smart and Trustworthy IoT System Interconnecting Legacy IR Devices

Abstract

Legacy-infrared (IR) devices are pervasively used. They are often controlled by IR remotes and cannot be controlled over the Internet. A trustworthy and cost-effective smart IR system that is able to change an IR controllable device into a smart Internet of Things (IoT) device and interconnect them for smart city/home applications is offered in this article. First, a printed circuit board (PCB) consisting of an IR receiver and multiple IR transmitters side by side which are capable of transmitting about 20 m indoors is designed and implemented. This IR transceiver board is the first of its kind. Second, the IR transceiver can be linked up with a Raspberry Pi, for which we develop two software tools, recording and replaying any IR signals so as to put the corresponding IR device in control. Third, a smartphone can be connected to the Pi by means of a message queuing telemetry transport (MQTT) cloud server so that the commands can be sent by the smartphone to the legacy IR device over the Internet. We have also identified the deficiency of TLS mutual authentication implemented by the popular MQTT open-source package Mosquitto for a trustworthy IoT system and patched the system. We analyze the factors that affect the IR signal transmission distance, discuss the security concerns of our IR transceiver, and illustrate the scenarios for attacks. For instance, TV can be turned off remotely by a drone equipped with the transceiver.