Reset- and Reconnection-based Covert Channels in CoAP
Laura Hartmann, Sebastian Zillien, Steffen Wendzel · 2021
The Internet of Things (IoT) and the Industrial Internet of Things (IIoT) are fast growing areas. Therefore, several protocols are specifically designed for these domains. CoAP (Constrained Application Protocol) is one of the more common ones. This lightweight protocol typically communicates over UDP, but can also use TCP and other carrier protocols, and is particularly suitable for embedded systems. In this work, we investigate CoAP with respect to covert communication and explore a new network hiding technique that is based on Artificial Resets. In addition, we investigate another covert channel by using the pattern PT15 Artificial Reconnections. We also propose and discuss detection methods for both covert channels.