Secure Node Identification Through Covert Clock Feature Extraction

Node identification is the first line of defense for wireless networks' security that prevents illegal devices from accessing the network. Hardware features originating from innate hardware imperfections are considered promising identification fingerprints, among which, the hardware clock feature has been put under the spotlight due to its prevalence and ease of extraction. Current extractions of hardware clock features over wireless networks rely on the transmissions of time information, which, per se, face significant threats such as spoofing and replay attacks. In this paper, we propose a covert method to extract the hardware clock features which avoids the time information transmissions. We further propose a tailored secure node identification approach based on the proposed covert clock feature extraction. We implement and evaluate the proposed approach on a real Long Range (LoRa) testbed consisting of heterogeneous LoRa end nodes. Experimental results demonstrate that the proposed approach could effectively identify the heterogeneous LoRa end nodes with 95% accuracy.