WiStealth: A Fixed Point RSSI Covert Channel using Multi-Modality Filtering Techniques

Abstract

Wireless networks are abundant throughout public spaces and medical facilities. Health monitoring systems may employ the use of wireless communication for data observation and collection in a Dynamic Data Driven Application System (DDDAS). Receive Signal Strength Indicator (RSSI) is a metric to evaluate the performance of two wireless devices and it can be leveraged as a medium for a covert channel. This paper proposes a novel approach in utilizing the observation of RSSI measurements at a wireless receiver as a covert channel. By fluctuating the transmitting power of a wireless emitter, the peak and troughs of an observation can be evaluated as a message. Additionally, RSSI as a metric is significantly hindered by noise and interference. Thus, the hindrance presents a challenge when RSSI is employed as a covert channel. To address such a challenge, we apply wavelet transforms to denoise the measurements of RSSI for when we fluctuate the transmitting power. Our realworld evaluation demonstrates the applicability, accuracy, and performance of the proposed approach in DDDAS