To Obtain or not to Obtain CSI in the Presence of Hybrid Adversary
This work addresses secure communication challenges in wireless networks for scenarios involving adversarial interference, but it is incremental as it builds on existing wiretap channel models with specific CSI considerations.
The paper tackles the problem of secure communication in a wiretap channel with a hybrid adversary that can jam or eavesdrop, analyzing how different methods of obtaining channel state information (CSI) affect achievable secrecy rates. The results show that main CSI is more valuable to the adversary than jamming CSI, and in some ergodic cases, no CSI can lead to higher secrecy rates than with CSI.
We consider the wiretap channel model under the presence of a hybrid, half duplex adversary that is capable of either jamming or eavesdropping at a given time. We analyzed the achievable rates under a variety of scenarios involving different methods for obtaining transmitter CSI. Each method provides a different grade of information, not only to the transmitter on the main channel, but also to the adversary on all channels. Our analysis shows that main CSI is more valuable for the adversary than the jamming CSI in both delay-limited and ergodic scenarios. Similarly, in certain cases under the ergodic scenario, interestingly, no CSI may lead to higher achievable secrecy rates than with CSI.