The ability to transmit a message securely in the presence of eavesdroppers in a dense wireless network is considered. As with a number of recent schemes, system nodes other than the transmitter and receiver are chosen to generate noise that confuses the eavesdropper. By exploiting the dynamics of the fading, significantly improved performance is achieved beyond that generated from the standard...

In this paper, we study covert communications between a pair of legitimate transmitter-receiver against watchful warden over slow fading channels. There coexist multiple friendly helper nodes who are willing to protect the communication from being detected by warden. We propose an uncoordinated jammer selection scheme where those helpers whose instantaneous channel gains receiver fall below pre...

Physical layer security is a sought-after concept to complement the established upper techniques in wireless communications. An appealing approach achieve physical use cooperative jamming with interference that known and suppressible by legitimate receiver but unknown to, hence not by, eavesdropper. Suppressing (KI), however, challenging due numerous unknowns, including carrier sampling frequen...

Multi-radio (multi-interface, multi-channel) 802.11 and sensor networks have been proposed to increase network capacity and to reduce energy consumption, to name only a few of their applications. They are vulnerable, however, to jamming attacks, in which attackers block communication by radio interference or MAC-protocol violation. Two jamming countermeasures have been proposed, namely software...