Covert Timing Channels for IoT over Mobile Networks

Various security threats have prompted covert timing channels to become an important alternative for the transmission of confidential information in an untrusted Internet of Things (IoT). This article aims to demonstrate the susceptibility of IoT to covert timing channels over mobile networks. It presents the system model of a covert timing channel for IoT and then analyzes whether the traditional covert timing channels based on inter-packet delays apply to IoT over 4G/5G networks. Given that there are so many covert timing channels proposed for computer networks, we investigate different kinds of construction approaches of covert timing channels to illustrate the feasibility of building covert timing channels for IoT, including packet-reordering-based, rateswitching- based, packet-loss-based, retransmission- based, and scheduling-based covert timing channels. Furthermore, this article also discusses several detection methods of revealing and preventing covert timing channels for IoT.