In this paper, the individual secrecy of two-way wiretap channel is investigated, where two legitimate users' messages are separately guaranteed secure against an external eavesdropper. For one thing, in some communication scenarios, the joint secrecy is impossible to achieve both positive secrecy rates of two users. For another, the individual secrecy satisfies the secrecy demand of many practical communication systems. Thus, firstly, an achievable secrecy rate region is derived for the general two-way wiretap channel with individual secrecy. In a deterministic channel, the region with individual secrecy is shown to be larger than that with joint secrecy.Secondly, outer bounds on the secrecy capacity region are obtained for the general two-way wiretap channel and for two classes of special two-way wiretap channels.The gap between inner and outer bounds on the secrecy capacity region is explored via the binary input two-way wiretap channels and the degraded Gaussian two-way wiretap. Most notably, the secrecy capacity regions are established for the XOR channel and the degraded Gaussian two-way wiretap channel.Furthermore, the secure sum-rate of the degraded Gaussian two-way wiretap channel under the individual secrecy constraint is demonstrated to be strictly larger than that under the joint secrecy constraint.In this paper, the individual secrecy of two-way wiretap channel is investigated, where two legitimate users' messages are separately guaranteed secure against an external eavesdropper. For one thing, in some communication scenarios, the joint secrecy is impossible to achieve both positive secrecy rates of two users. For another, the individual secrecy satisfies the secrecy demand of many practical communication systems. Thus, firstly, an achievable secrecy rate region is derived for the general two-way wiretap channel with individual secrecy. In a deterministic channel, the region with individual secrecy is shown to be larger than that with joint secrecy.Secondly, outer bounds on the secrecy capacity region are obtained for the general two-way wiretap channel and for two classes of special two-way wiretap channels.The gap between inner and outer bounds on the secrecy capacity region is explored via the binary input two-way wiretap channels and the degraded Gaussian two-way wiretap. Most notably, the secrecy capacity regions are established for the XOR channel and the degraded Gaussian two-way wiretap channel.Furthermore, the secure sum-rate of the degraded Gaussian two-way wiretap channel under the individual secrecy constraint is demonstrated to be strictly larger than that under the joint secrecy constraint.

arXiv:1707.05930Jul 19, 20171 citation

The Big Secret

Merle Colby, David A. Katcher

Physics TodayOct 1, 19490 citations

Secrecy outage of a two-user slow fading broadcast channel

Bo Wang, Pengcheng Mu, Hui‐Ming Wang +1 more

The secrecy outage of a two-user slow fading broadcast channel is studied in this paper. We consider the scenario where independent and confidential messages are transmitted to each user using superposition coding in the presence of an external eavesdropper. We assume the instantaneous channel state information (CSI) of the eavesdropper's channel is not available and the secrecy outage can be claimed for each user. The secrecy outage probability of each user conditioned on the instantaneous CSI of the legitimate channel is studied and used to derive the achievable secrecy rate region under the conditional secrecy outage probability constraints. The average achievable secrecy rate, i.e. the secrecy throughput, is studied as the measure of performance under the slow fading. The optimal secrecy rate allocation strategy that achieves the boundary of the achievable secrecy throughput region is characterized for the general case and for the maximum sum secrecy throughput. Numerical results of the secrecy throughput regions are shown, and the parameters that influence the secrecy throughput are discussed.The secrecy outage of a two-user slow fading broadcast channel is studied in this paper. We consider the scenario where independent and confidential messages are transmitted to each user using superposition coding in the presence of an external eavesdropper. We assume the instantaneous channel state information (CSI) of the eavesdropper's channel is not available and the secrecy outage can be claimed for each user. The secrecy outage probability of each user conditioned on the instantaneous CSI of the legitimate channel is studied and used to derive the achievable secrecy rate region under the conditional secrecy outage probability constraints. The average achievable secrecy rate, i.e. the secrecy throughput, is studied as the measure of performance under the slow fading. The optimal secrecy rate allocation strategy that achieves the boundary of the achievable secrecy throughput region is characterized for the general case and for the maximum sum secrecy throughput. Numerical results of the secrecy throughput regions are shown, and the parameters that influence the secrecy throughput are discussed.

GlobecomDec 1, 20143 citations

On the Optimum Secrecy Outage Probability and Ergodic Secrecy Rate over Wireless Channels

Clément Leroy, Tarak Arbi, Benoît Geller +1 more

We study the secrecy of wireless channels in the presence of an eavesdropper, where the channels are random and the transmitter only has knowledge of the channel statistics. We investigate the optimal input distribution with respect to several secrecy metrics: the Secrecy Outage Probability (SOP), defined as the probability that the coding rate $r$ exceeds the instantaneous secrecy rate; the Ergodic Secrecy Rate (ESR), defined as the expected secrecy rate over channel realizations; and the Ergodic Positive Secrecy Rate (EPSR), defined as the expected value of the positive part of the secrecy rate. We introduce two partial orderings for random channels: the uniformly less noisy order and the less noisy on average order. We show that when the main channel is uniformly less noisy than the eavesdropper channel, the optimal input distribution is a non-precoded Gaussian input for both the SOP and the EPSR. Furthermore, we show that the same input distribution is optimal for the ESR when the less noisy on average order holds. In addition, similar optimality results for the SOP and the EPSR are obtained for single-transmit-antenna channels without requiring any channel ordering assumptions. Closed-form expressions of the secrecy metrics are derived for special cases of Rayleigh fading channels.We study the secrecy of wireless channels in the presence of an eavesdropper, where the channels are random and the transmitter only has knowledge of the channel statistics. We investigate the optimal input distribution with respect to several secrecy metrics: the Secrecy Outage Probability (SOP), defined as the probability that the coding rate $r$ exceeds the instantaneous secrecy rate; the Ergodic Secrecy Rate (ESR), defined as the expected secrecy rate over channel realizations; and the Ergodic Positive Secrecy Rate (EPSR), defined as the expected value of the positive part of the secrecy rate. We introduce two partial orderings for random channels: the uniformly less noisy order and the less noisy on average order. We show that when the main channel is uniformly less noisy than the eavesdropper channel, the optimal input distribution is a non-precoded Gaussian input for both the SOP and the EPSR. Furthermore, we show that the same input distribution is optimal for the ESR when the less noisy on average order holds. In addition, similar optimality results for the SOP and the EPSR are obtained for single-transmit-antenna channels without requiring any channel ordering assumptions. Closed-form expressions of the secrecy metrics are derived for special cases of Rayleigh fading channels.

arXiv:2604.22587Apr 24, 20260 citations

Must We Hide?

Ralph E. Lapp, Robert R. Wilson

Physics TodaySep 1, 194917 citations

r

exceeds the instantaneous secrecy rate; the Ergodic Secrecy Rate (ESR), defined as the expected secrecy rate over channel realizations; and the Ergodic Positive Secrecy Rate (EPSR), defined as the expected value of the positive part of the secrecy rate. We introduce two partial orderings for random channels: the uniformly less noisy order and the less noisy on average order. We show that when the main channel is uniformly less noisy than the eavesdropper channel, the optimal input distribution is a non-precoded Gaussian input for both the SOP and the EPSR. Furthermore, we show that the same input distribution is optimal for the ESR when the less noisy on average order holds. In addition, similar optimality results for the SOP and the EPSR are obtained for single-transmit-antenna channels without requiring any channel ordering assumptions. Closed-form expressions of the secrecy metrics are derived for special cases of Rayleigh fading channels.