Fast-Forward Mitigation Schemes for Cognitive Adversary

Abstract

We address a denial of service attack on low-latency communication, wherein a cognitive adversary, armed with a full-duplex radio, can simultaneously measure the energy levels on the victim’s frequency band besides jamming it. First, we show that traditional countermeasures such as frequency hopping cannot mitigate such attacks. To circumvent this problem, we propose two cooperative relaying schemes, namely: semi-coherent fast-forward half-duplex and semi-coherent fast-forward full-duplex relaying schemes, wherein the victim node seeks the assistance of a helper node in its vicinity, that can either work in half-duplex or full-duplex mode, to instantaneously multiplex the victim’s messages in its message to the destination. In the former scheme, the victim is required to continue transmission on the jammed band, whereas the helper node is asked to overhear the victim’s frequency band to multiplex their information in its frequency band. In the latter scheme, the victim and the helper node cooperatively pour fraction of their power on both frequency bands so as to reliably communicate their messages on the helper’s frequency band. Extensive analysis on the choice of the power splitting factor between the frequency bands is presented besides proving that both schemes successfully engage the adversary on the jammed frequency band.