Full-duplex Eavesdropper Research Articles

Concurrent Spoofing-Jamming Attack in Massive MIMO Systems With a Full-Duplex Multi-Antenna Eavesdropper

In this paper, we evaluate the ultimate severity of a concurrent spoofing-jamming un-detected attack from a full-duplex (FD) multi-antenna eavesdropper (EV) on a legitimate user equipment (UE) in a massive multiple-input multiple-output (MIMO) system. The FD EV can concurrently exploit its antennas to spoof one UE pilot and to estimate its link to the same UE in the uplink, and then to eavesdrop the UE's data and perform directional jamming in the downlink. From the perspective of the EV, we derive an expression for the ergodic rate difference, which is general for any possible overlap between spoofing and jamming antenna subsets. Residual spoofing and jamming self-interferences and their statistical dependencies are accounted for in the derived expression. The EV optimizes the trade-off between both spoofing-jamming powers, and antenna subsets to minimize the ergodic rate difference. Numerical results show that the EV is capable of destroying the security of the legitimate communication with a small number of antennas and a power budget equal to that of the attacked UE. The severity of the attack depends on the EV's knowledge of the power allocation strategies used at the base station (BS).

Optimal Power Allocation for Energy-Efficient Data Transmission Against Full-Duplex Active Eavesdroppers in Wireless Sensor Networks

This paper studies an optimal transmit power decision policy for energy-efficient data transmissions between a sensor node (i.e., the source) and a cluster head (i.e., the destination) in cluster-based wireless sensor networks in the presence of a full-duplex (FD) active eavesdropper. In this network, the source is powered by a wireless energy harvester, while the destination is constantly supplied by the traditional electrical energy. The eavesdropper is capable of FD transmitting and receiving and hence opportunistically launches jamming attacks against the destination while eavesdropping, which affects not just the legitimate transmissions but the eavesdropper itself. The destination can also work in the FD mode to simultaneously receive information signals and send an artificial noise to interfere with the eavesdropper. Therefore, we investigate an optimal power allocation policy for the source in order to maximize the secrecy transmission rate against an FD eavesdropper. In addition, we study the problem of decision making in two different scenarios. First, the legitimate nodes are assumed to have prior information about the arrival of harvested energy and about the eavesdropper’s jamming attack model. The problem is formulated as the framework of a partially observable Markov decision process and is solved with value iteration–based dynamic programming. Second, the legitimate nodes do not know the dynamics of the environment in advance, so the problem becomes a standard Markov decision process. Hence, we propose an actor-critic learning framework to find the solution from practical interactions with the environment. Finally, we verify the performance of the proposed schemes by simulations.

Pilot Contamination for Active Eavesdropping

Existing studies on physical layer security often assume the availability of perfect channel state information (CSI) and overlook the importance of channel training needed for obtaining the CSI. In this letter, we discuss how an active eavesdropper can attack the training phase in wireless communication to improve its eavesdropping performance. We derive a new security attack from the pilot contamination phenomenon, which targets at systems using reverse training to obtain the CSI at the transmitter for precoder design. This attack changes the precoder used by the legitimate transmitter in a controlled manner to strengthen the signal reception at the eavesdropper during data transmission. Furthermore, we discuss an efficient use of the transmission energy of an advanced full-duplex eavesdropper to simultaneously achieve a satisfactory eavesdropping performance whilst degrading the detection performance of the legitimate receiver.