As many security solutions integrated with various technologies have been proposed against eavesdropping attacks, technical advances for adversaries can also pose a serious security threat. This paper considers a problem of smart eavesdropping attacks on multiple-input-multiple-output wiretap channels for a legitimate transceiver. We present a smart eavesdropper model and a cooperative jamming solution between transceivers that can control the jamming signal power to achieve the optimal secrecy performance. In particular, for practical applications, our proposed solution considers the residual self-interference from the full-duplex receiver and the limited cancellation capability of the smart eavesdropper. We derive the secrecy outage probability in general and smart eavesdropper cases, and show numerical results and secrecy regions for evaluation. As a result, our proposed solutions can improve the secrecy performance significantly by exploiting the full-duplex receiver and the cooperative jamming strategies with the sophisticated power control according to power expenditure.
As many security solutions integrated with various technologies have been proposed against eavesdropping attacks, technical advances for adversaries can also pose a serious security threat. This paper considers a problem of smart eavesdropping attacks on multiple-input-multiple-output wiretap channels for a legitimate transceiver. We present a smart eavesdropper model and a cooperative jamming solution between transceivers that can control the jamming signal power to achieve the optimal secrecy performance. In particular, for practical applications, our proposed solution considers the residual self-interference from the full-duplex receiver and the limited cancellation capability of the smart eavesdropper. We derive the secrecy outage probability in general and smart eavesdropper cases, and show numerical results and secrecy regions for evaluation. As a result, our proposed solutions can improve the secrecy performance significantly by exploiting the full-duplex receiver and the cooperative jamming strategies with the sophisticated power control according to power expenditure.
Security issue is of paramount importance yet significant challenge for wireless communications, and this problem can be even more intricate when facing with a full-duplex adversary. In this paper, we investigate the physical layer security of a legitimate transmission link in the presence of a full-duplex active eavesdropper, who is capable to perform eavesdropping and jamming simultaneously. The legitimate user aims at a target secrecy rate while the eavesdropper intends to maximize its wiretap rate. To this end, the eavesdropper imposes a jamming signal at the legitimate receiver to stimulate higher-power legitimate transmissions and thus facilitates its eavesdropping. This, however, generates residual self-interference at the eavesdropper itself and is subject to a linear price for the jamming power. The problem is then formulated within a game-theoretic framework, where the closed-form strategies of both the legitimate user and active eavesdropper are obtained. Moreover, we analyze the performance in terms of secrecy outage probability for the legitimate link in such a hostile situation. Also provided are the simulation results which validate our theoretical analysis.
Full-duplex (FD) jamming transceivers recently have been shown to enhance the information security of wireless communication systems by simultaneously transmitting artificial noise (AN) while receiving information. In this paper, we investigate whether FD jamming can also improve the system's secrecy energy efficiency (SEE) in terms of securely communicated bits per Joule when considering the additional power used for jamming and self-interference (SI) cancellation. Moreover, the degrading effect of the residual SI is also taken into account. In this regard, we formulate a set of SEE maximization problems for a FD multiple-input-multiple-output multiple-antenna eavesdropper (MIMOME) wiretap channel, considering both cases where exact or statistical channel state information (CSI) is available. Due to the intractable problem structure, we propose iterative solutions in each case with a proven convergence to a stationary point. Numerical simulations indicate only a marginal SEE gain, through the utilization of FD jamming, for a wide range of system conditions. However, when SI can efficiently be mitigated, the observed gain is considerable for scenarios with a small distance between the FD node and the eavesdropper, a high signal-to-noise ratio (SNR), or for a bidirectional FD communication setup.
Security has become an increasingly important issue in wireless communications for the IoT (Internet of Things) environments, to which physical layer approaches can contribute by differentiating desired transceiver and wiretap channels for security of confidential data. In this paper, we propose an optimal power allocation strategy for practical physical-layer security, based on friendly jamming with cancellation for anti-eavesdropping. In particular, secrecy outage probability is evaluated in scenarios involving a pair of transmitter-receiver and a passive eavesdropper near the receiver. We derive the optimal power allocation strategy and the required cancellation capability to enhance secrecy performance. Numerical results verify the tradeoff between jamming power ratio and cancellation capability. Furthermore, our proposed scheme can achieve the improved secrecy rate regardless of availability of eavesdropper channel information.
Self-interference cancellation technologies enable full-duplex operation at the eavesdropper. In addition to wiretapping, the eavesdropper simultaneously tries to reduce the secrecy rate of the illegitimate transmitter-receiver pair by jamming its receiver. On the other hand, the transmitter-receiver pair aims to increase its secrecy rate. To examine the power decision processes between the transmitter and the eavesdropper, we propose a novel physical layer security game in the wiretap channel, where the eavesdropper operates in a full-duplex mode. To analyse the game outcome, a distributed learning algorithm is adopted to achieve the mixed-strategy Nash equilibrium. Based on the equilibrium, we provide a switch strategy for the eavesdropper to determine the optimal operation mode between the full-duplex and half-duplex, depending on its location and self-interference. Numerical results show that the switch strategy improves the eavesdropper's performance in the sense of decreasing the secrecy rate.
In this paper, we introduce smart jamming attack by an active eavesdropper (or jammer) who is capable of full-duplex communications. Using self-interference cancellation, the active eavesdropper can have no degraded signals from jamming, while the powers of jamming signals can be decided to manipulate a legitimate transmitter's transmission powers in decreasing the secrecy rate when the legitimate transmitter is unaware of the jammer's capability of full-duplex communications. We derive a closed-form expression for an upper-bound on the secrecy rate and use it to allocate the jamming powers. From this, we can show that the secrecy rate can be zero under full-duplex attack for any total transmission power of the legitimate transmitter. This result demonstrates that a transmitter should be aware of the possibility of active eavesdropping with jamming attack.
Security is an issue of paramount importance, yet is it a significant challenge for wireless communications, which becomes more intricate when facing a full duplex (FD) active eavesdropper capable of performing eavesdropping and jamming simultaneously. In this paper, we investigate the physical layer security issue in the presence of an FD active eavesdropper, who launches jamming attacks to further improve the eavesdropping. The jamming, however, also results in self-interference at the eavesdropper itself. This security problem is formulated within a hierarchical game framework where the eavesdropper acts as the leader and the legitimate user is the follower. In particular, we first investigate the follower's secrecy rate maximization problem and derive the optimal legitimate transmission strategy. Then, the leader's wiretap rate maximization is expressed as a mathematical program with equilibrium constraints (MPEC). Leveraging the concavity of the follower's problem, we transform the MPEC problem into a single-level optimization and obtain the jamming power allocation strategy by applying the primal-dual interior-point method. Moreover, we analyze the situations where only partial channel state information is available at the legitimate user and the corresponding impacts on the game. Finally, we present extensive simulation results to validate our theoretical analysis.