Covert communication with finite blocklength in AWGN channels

Yan, Shihao; He, Biao; Cong, Yirui; Zhou, Xiangyun

doi:10.1109/icc.2017.7996337

Cited by 50 publications

(27 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Considering additive white Gaussian noise (AWGN) channels, a square root law was established in [3], which states that Alice can transmit no more than O( √ n) bits in n channel uses covertly and reliably to Bob. Besides, some works in the literature focused on the design and performance analysis of covert communications in practical application scenarios, for example, by considering unknown background noise power [11], ignorance of transmission time [12], noise uncertainty [13], delay constraints [14], [15], channel uncertainty [16], practical modulation [17], uninformed jamming [18], relay networks [19], [20], broadcast channels [21], key generation [22], and artificial noise [23], [24]. In covert communications, for an optimal detector at Willie, we have ξ * = 1 − V T (p 0 , p 1 ), where ξ * is the minimum detection error probability and V T (p 0 , p 1 ) is the total variation between the likelihood function p 0 (y) of the observation y under the null hypothesis (when Alice does transmit to Bob) and the likelihood function p 0 (y) under the alternative hypothesis (when Alice transmits to Bob).…”

mentioning

confidence: 99%

Gaussian Signalling for Covert Communications

Yan

Cong

Hanly

et al. 2019

IEEE Trans. Wireless Commun.

Self Cite

144

View full text Add to dashboard Cite

In this work, we examine the optimality of Gaussian signalling for covert communications with an upper bound on D(p 1 ||p 0 ) or D(p 0 ||p 1 ) as the covertness constraint, where D(p 1 ||p 0 ) and D(p 0 ||p 1 ) are different due to the asymmetry of Kullback-Leibler divergence, p 0 (y) and p 1 (y) are the likelihood functions of the observation y at the warden under the null hypothesis (no covert transmission) and alternative hypothesis (a covert transmission occurs), respectively. Considering additive white Gaussian noise at both the receiver and the warden, we prove that Gaussian signalling is optimal in terms of maximizing the mutual information of transmitted and received signals for covert communications with an upper bound on D(p 1 ||p 0 ) as the constraint. More interestingly, we also prove that Gaussian signalling is not optimal for covert communications with an upper bound on D(p 0 ||p 1 ) as the constraint, for which as we explicitly show skew-normal signalling can outperform Gaussian signalling in terms of achieving higher mutual information. Finally, we prove that, for Gaussian signalling, an upper bound on D(p 1 ||p 0 ) is a tighter covertness constraint in terms of leading to lower mutual information than the same upper bound on D(p 0 ||p 1 ), by proving D(p 0 ||p 1 ) ≤ D(p 1 ||p 0 ).

show abstract

mentioning

confidence: 99%

Gaussian Signalling for Covert Communications

Yan

Cong

Hanly

et al. 2019

IEEE Trans. Wireless Commun.

Self Cite

144

View full text Add to dashboard Cite

show abstract

“…Specifically, covert transmission rate maximization under a noise uncertainty model was considered in [12] and [13], where Willie's detector was assumed to be a robust and a Bayesian statistics-based radiometer, respectively. [14] and [15] investigated LPD communication with finite length codewords, and the authors maximized the total number of information bits that can be transmitted under the constraint that the error probability of Willie's detector is higher than a threshold. In [16], the authors proposed to use multiple relays to forward the private message covertly, and provided algorithms to find the optimal routing scheme that maximizes the covert throughput or minimizes the end-to-end delay.…”

Section: A Related Workmentioning

confidence: 99%

LPD Communication: A Sequential Change-Point Detection Perspective

Huang

Wang

Towsley

et al. 2020

IEEE Trans. Commun.

View full text Add to dashboard Cite

In this paper, we establish a framework for low probability of detection (LPD) communication from a sequential change-point detection (SCPD) perspective, where a transmitter, Alice, wants to hide her signal transmission to a receiver, Bob, under the surveillance of an adversary, Willie. The new framework facilitates to model LPD communication and further evaluate its performance under the condition that Willie has no prior knowledge on when the transmission from Alice starts and that Willie wants to detect the existence of the communication as quickly as possible in real-time manner. We consider three different sequential tests for Willie, i.e., the Shewhart test, the cumulative sum (CUSUM) test, and the Shiryaev-Roberts (SR) test, to model the detection procedure. Communication is said to be covert if it stops before detection by Willie with high probability. Covert probability defined as the probability that Willie is not alerted during the communication procedure is investigated. We formulate an optimization problem aimed at finding the transmit power and transmission duration such that the total amount of information that can be transmitted is maximized subject to a high covert probability. Under Shewhart test, closed-form approximations of the optimal transmit power and transmission duration are derived, which well approximate the solutions obtained from exhaustive search. As for CUSUM and SR tests, we provide an effective algorithm to search the optimal solution. Numeric results are presented to show the performance of LPD communication.

show abstract

“…The covert communication with interference uncertainty from non-cooperative transmitters is studied in [19]. The effect of finite blocklength (i.e., short delay constraints) over AWGN channels on covert communications was examined in [20], which proves that the effective throughput of covert communications is maximized when all available channel uses are utilized. A covert communication system under block fading channels was examined in [21], [22], where transceivers have uncertainty on the related channel state information.…”

Section: Introductionmentioning

confidence: 99%

Covert Wireless Communications With Channel Inversion Power Control in Rayleigh Fading

Yan

Zhou

et al. 2019

IEEE Trans. Veh. Technol.

Self Cite

View full text Add to dashboard Cite

In this work, we adopt channel inversion power control (CIPC) to achieve covert communications aided by a full-duplex receiver. Specifically, the transmitter varies the power and phase of transmitted signals as per the channel to the receiver, such that the receiver can decode these signals without knowing the channel state information. This eliminates the required feedback from the transmitter to the receiver, which aids hiding the transmitter from a warden. The truncated CIPC and conventional CIPC schemes are proposed and examined, where for truncated CIPC covert transmission ceases when the channel quality from the transmitter to the receiver is low, while for conventional CIPC covert transmission always occurs regardless of this channel quality. We examine their performance in terms of the achieved effective covert throughput (ECT), which quantifies the amount of information that the transmitter can reliably convey to the receiver, subject to the constraint that the warden's detection error probability is no less than some specific value. Our examination shows that the truncated CIPC scheme can outperform the conventional CIPC scheme due to this constraint.Index Terms-Physical layer security, covert communications, full duplex, artificial noise.

show abstract

Covert communication with finite blocklength in AWGN channels

Cited by 50 publications

References 18 publications

Gaussian Signalling for Covert Communications

Gaussian Signalling for Covert Communications

LPD Communication: A Sequential Change-Point Detection Perspective

Covert Wireless Communications With Channel Inversion Power Control in Rayleigh Fading

Contact Info

Product

Resources

About