Covert Communication Achieved by a Greedy Relay in Wireless Networks

Abstract

Covert wireless communication aims to hide the very existence of wireless transmissions in order to guarantee a strong security in wireless networks. In this work, we examine the possibility and achievable performance of covert communication in amplify-and-forward one-way relay networks. Specifically, the relay is greedy and opportunistically transmits its own information to the destination covertly on top of forwarding the source's message, while the source tries to detect this covert transmission to discover the illegitimate usage of the resource (e.g., power, spectrum) allocated only for the purpose of forwarding the source's information. We propose two strategies for the relay to transmit its covert information, namely rate-control and powercontrol the transmission schemes, for which the source's detection limits are analysed in terms of detection error probability and the achievable effective covert rates from the relay to destination are derived. Our examination determines the conditions under which the rate-control transmission scheme outperforms the powercontrol transmission scheme, and vice versa, which enables the relay to achieve the maximum effective covert rate. Our analysis indicates that the relay has to forward the source's message to shield its covert transmission and the effective covert rate increases with its forwarding ability (e.g., its maximum transmit power).

A Wireless Covert Channel Based on Constellation Shaping Modulation

“…Taking plane, for example, with the vector residual, of residual signal and the corresponding center line value shared between the sender and the receiver, the secret message bits can be demodulated with (14). The demodulation in plane works in the same way.…”

“…Several kinds of wireless covert channels have been proposed [6][7][8][9][10][11][12][13][14][15][16]. In [7,13], the secret data is embedded in the redundant fields of wireless communication protocols such as padding of frames, headers of the MAC, RLC, and PDCP.…”

“…In [12], several wireless covert channels are introduced with the secret data embedded in the phase of short training field, the frequency of long training field, and cyclic prefix in WiFi system. In [14,15], the secret data are transmitted by covert relay on top of the cover data in wireless relay networks. In [16], the wireless covert channels are presented based on the coordinated operations in the control channel and data channel of MIMO system.…”

Performance evaluation of amplify‐and‐forward relaying cooperative vehicular networks under physical layer security

“…Proof. By invoking the CDFs F SE (x) and F Ψ 2 (x) into (19) and differentiating it with respect to x with the help of 34(eq. 1.14.1.4) and after some simplifications, we can obtain the PDF Λ (II) E (x) as given in (21).…”

“…8 PHY-security can be implemented without consuming the additional communication resources or infrastructures, and it can guarantee information confidentiality with the aid of appropriate coding and signal processing techniques. Recently, PHY-security in cooperative relaying networks has been widely studied in the literature (see other works [9][10][11][12][13][14][15][16][17][18][19] and the references therein). Specifically, Zou et al, 9 Yang et al, 10 and Nguyen and Kim 11 have investigated the secrecy performance of cooperative multirelay networks with optimal relay selection scheme.…”