# A Novel Covert Channel for IEEE 802.11 Networks Utilizing MAC Address Randomization
## 9 Conclusions  
This study focuses on the design and implementation of a covert channel disguised as MAC address randomization. The implementation was thoroughly tested through simulations on IEEE 802.11 ac wireless networks, and it involved three distinct scenarios to assess the covert channel's performance. One significant advantage of the presented covert channel is its potential to remain unnoticed. It achieves this by utilizing disposable random MAC addresses for wireless network scanning, which are typically perceived as having no purpose other than concealing the device's identity. This attribute allows the covert channel to be deeply camouflaged within the network infrastructure. Moreover, the implementation of the covert channel is straightforward, transparent, and capable of coexisting harmoniously with other stations generating regular network traffic without causing any disruptions. One limitation of the covert channel is its reliance on an AP as the intended recipient of covert messages to ensure reliability. This requirement may introduce some level of suspicion since the covert channel needs to maintain the appearance of regular scanning processes by generating probe requests at the expected rate. This aspect should be taken into consideration when deploying the covert channel to mitigate any potential suspicions or anomalies that may arise. In terms of future research directions, there are two key aspects to consider: improving the robustness and resistance to steganalysis by adopting the recommended MAC randomization practices and analyzing the impact of the offered load on the covert channel. To enhance the covert channel's robustness and make it more resilient against steganalysis techniques, it is crucial to explore strategies beyond MAC randomization. Current techniques based on probe request fingerprinting can easily detect MAC randomization and retrieve the global MAC address. To address this limitation, randomizing additional fields, such as sequence numbers, and altering device fingerprints could provide an added layer of undetectability, making the covert channel more effective and covert. Additionally, investigating the impact of the offered load on the covert channel is essential. While it is established that the number of stations has an impact on the covert channel, understanding the influence of the offered load is equally important. By examining how the offered load affects the covert channel's performance, it becomes possible to better estimate the covert channel throughput during implementation and adapt it to match the network conditions. The impressive throughput, efficiency, minimal delay, and jitter achieved through the use of SWP make this covert channel an excellent choice for modern IEEE 802.11 wireless networks for dense environments. In typical network scenarios, the attained throughput is more than sufficient to establish a stable and reliable communication channel. In the context of a covert channel, it can be regarded as a high-throughput covert communication solution. Moreover, the covert channel offers versatility with its three modes of operation, allowing for flexibility in adapting to different environmental conditions. The proposed covert channel offers applications in Wi-Fi networks to prevent targeting, in monitored networks to send imperceptible secret messages, and in device authentication to ensure the real identity of a station in a highly private network, where MAC address spoofing is a concern. Conceptualization, M.N. and G.T. ; methodology, M.N. and G.T. ; software, G.T. ; validation, G.T. ; formal analysis, M.N. and G.T. ; investigation, M.N. and G.T. ; writing--original draft preparation, M.N. and G.T. ; writing--review and editing, M.N. ; visualization, G.T. ; supervision, M.N. ; project administration, M.N. ; funding acquisition, M.N. All authors have read and agreed to the published version of the manuscript.