This paper considers a state dependent broadcast channel with one transmitter, Alice, and two receivers, Bob and Eve. The problem is to effectively convey ("amplify") the channel state sequence to Bob while "masking" it from Eve. The extent to which the state sequence cannot be masked from Eve is referred to as leakage. This can be viewed as a secrecy problem, where we desire that the channel state itself be minimally leaked to Eve while being communicated to Bob. The paper is aimed at characterizing the trade-off region between amplification and leakage rates for such a system. An achievable coding scheme is presented, wherein the transmitter transmits a partial state information over the channel to facilitate the amplification process. For the case when Bob observes a stronger signal than Eve, the achievable coding scheme is enhanced with secure refinement. Outer bounds on the trade-off region are also derived, and used in characterizing some special case results. In particular, the optimal amplification-leakage rate difference, called as differential amplification capacity, is characterized for the reversely degraded discrete memoryless channel, the degraded binary, and the degraded Gaussian channels. In addition, for the degraded Gaussian model, the extremal corner points of the trade-off region are characterized, and the gap between the outer bound and achievable rate-regions is shown to be less than half a bit for a wide set of channel parameters.
On the other hand, the problems of state amplification and state masking are individually solved in @cite_36 @cite_10 @cite_32 for point-to-point channels. Both @cite_36 @cite_10 and @cite_32 consider the problem of reliable transmission of messages in addition to state amplification and state masking respectively. In this paper, we consider the problem of amplifying the state to a desired receiver while trying to minimize the leakage (or mask the state) to the eavesdropper.
@cite_36 @cite_10 @cite_32
2050804383 2091539141 2022971840 2189096384
We formulate a problem of state information transmission over a state-dependent channel with states known at the transmitter. In particular, we solve a problem of minimizing the mean-squared channel state estimation error E spl par S sup n - S spl circ sup n spl par for a state-dependent additive Gaussian channel Y sup n = X sup n + S sup n + Z sup n with an independent and identically distributed (i.i.d.) Gaussian state sequence S sup n = (S sub 1 , ..., S sub n ) known at the transmitter and an unknown i.i.d. additive Gaussian noise Z sup n . We show that a simple technique of direct state amplification (i.e., X sup n = spl alpha S sup n ), where the transmitter uses its entire power budget to amplify the channel state, yields the minimum mean-squared state estimation error. This same channel can also be used to send additional independent information at the expense of a higher channel state estimation error. We characterize the optimal tradeoff between the rate R of the independent information that can be reliably transmitted and the mean-squared state estimation error D. We show that any optimal (R, D) tradeoff pair can be achieved via a simple power-sharing technique, whereby the transmitter power is appropriately allocated between pure information transmission and state amplification. We introduce a novel form of decoy-state technique to make the single-photon Bennett 1992 protocol robust against losses and noise of a communication channel. Two uninformative states are prepared by the transmitter in order to prevent the unambiguous state discrimination attack and improve the phase-error rate estimation. The presented method does not require strong reference pulses, additional electronics or extra detectors for its implementation. This paper presents a proposal of covert steganographic channels in high-speed IEEE 802.11n networks. The method is based on the modification of cyclic prefixes in OFDM (Orthogonal Frequency-Division Multiplexing) symbols. This proposal provides the highest hidden transmission known in the state of the art. This paper includes theoretical analysis and simulation results of the presented steganographic system performance. The simulation performance was compared with other known approaches in the literature. In this paper, we investigate secure transmission in untrusted amplify-and-forward half-duplex relaying networks with the help of cooperative jamming at the destination (CJD). Under the assumption of full channel state information (CSI), conventional CJD using self-interference cancelation at the destination is efficient when the untrusted relay has no capability to suppress the jamming signal. However, if the source and destination are equipped with a single antenna and the only untrusted relay is equipped with N multiple antennas, it can remove the jamming signal from the received signal by linear filters and the full multiplexing gain of relaying cannot be achievable with the conventional CJD due to the saturation of the secrecy rate at the high transmit power regime. We propose in this paper new CJD scheme where neither destination nor relay can acquire CSI of relay-destination link. Our proposed scheme utilizes zero-forcing cancelation based on known jamming signals instead of self-interference subtraction, while the untrusted relay cannot suppress the jamming signals due to the lack of CSI. We show that the secrecy rate of the proposed scheme can enjoy a half of multiplexing gain in half-duplex relaying while that of conventional CJD is saturated at high transmit power for N ≥2. The impact of channel estimation error at the destination is also investigated to show the robustness of the proposed scheme against strong estimation errors.