Fundamental limits of quantum-secure covert communication over bosonic channels

Bullock, Michael S.; Gagatsos, Christos N.; Guha, Saikat; Bash, Boulat A.

doi:10.48550/arxiv.1907.04228

Cited by 2 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A more careful calculation, similar to that in Ref. [23], shows that under the requirement of P E ≥ 1/2 − δ, the relative entropy D(ρ ⊗N additivity of relative entropy and thermal state properties,…”

Section: B Covertnessmentioning

confidence: 64%

“…An additional benefit of the EA communication protocol is its security and covertness [22,23]. Suppose that a passive adversary endeavors to detect Alice and Bob's communication attempt by monitoring the mode lost to the environment, but does not have access to the idler âI since entanglement is pre-shared prior to communication.…”

Section: B Covertnessmentioning

confidence: 99%

“…We first show that phase encoding on two-mode squeezed vacuum (TMSV) is asymptotically optimum (Section III A). Next, we show that such an EA communication protocol is in fact secure and allows one to break the square-root law of covert communication [23] by a logarithmic factor (Section III B). Then, we propose practical quantum receivers, based on prior results of Refs.…”

Section: Introductionmentioning

confidence: 97%

“…In particular, it is known [1] that the ratio of C E (Φ) /C (Φ) can diverge logarithmically with the inverse of signal power over a noisy and lossy bosonic channel [20]. Such an EA scenario is widely applicable to radiofrequency communication, deep space communication [21], and covert communication [22,23].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Practical Route to Entanglement-Assisted Communication Over Noisy Bosonic Channels

2020

View full text Add to dashboard Cite

Entanglement can offer substantial advantages in quantum information processing, but loss and noise hinder its applications in practical scenarios. Although it has been well known for decades that the classical communication capacity over lossy and noisy bosonic channels can be significantly enhanced by entanglement, no practical encoding and decoding schemes are available to realize any entanglement-enabled advantage. Here, we report structured encoding and decoding schemes for such an entanglement-assisted communication scenario. Specifically, we show that phase encoding on the entangled two-mode squeezed vacuum state saturates the entanglement-assisted classical communication capacity and overcomes the fundamental limit of covert communication without entanglement assistance. We then construct receivers for optimum hypothesis testing protocols under discrete phase modulation and for optimum noisy phase estimation protocols under continuous phase modulation. Our results pave the way for entanglement-assisted communication and sensing in the radiofrequency and microwave spectral ranges. I. INTRODUCTIONEntanglement's benefit for quantum information processing has been revealed by pioneer works in communication [1], sensing [2-4], and computation [5]. Notably, the entanglement-enabled advantages even survive loss and noise in certain scenarios, as predicted [6][7][8] and experimentally demonstrated [9][10][11] in the entanglementenhanced sensing protocol called quantum illumination.It is also known, in theory, that pre-shared entanglement increases the classical communication capacity, i.e., the maximum rate of reliable communication of classical bits (cbits), over a quantum channel Φ. In an ideal case, the superdense-coding [12] protocol allows for sending two cbits on a single qubit, with the assistance of one entanglement bit (ebit). Formally, one characterizes the rate limit of such EA communication by the classical capacity with unlimited entanglement-assistance [1,[13][14][15], C E (Φ) [16]. Compared with the classical capacity without entanglement-assistance, i.e., the Holevo-Schumacher-Westmoreland capacity, C (Φ) [17][18][19], the improvement enabled by entanglement can be drastic even over a noisy channel Φ. In particular, it is known [1] that the ratio of C E (Φ) /C (Φ) can diverge logarithmically with the inverse of signal power over a noisy and lossy bosonic channel [20]. Such an EA scenario is widely applicable to radiofrequency communication, deep space communication [21], and covert communication [22,23].Despite the large advantage of EA capacity, a practical EA encoding and decoding scheme that achieves any advantage over the classical capacity is unknown in the high noise regime. Previous experiments [24,25] focused on ideal scenarios with qubits; Although the EA capac- * zhuangquntao@email.arizona.edu ity formula for bosonic Gaussian channel is well established [26,27], the achievability proof in Ref.[1] relies on approximating an infinite dimensional channel as a channel with finite but large d...

show abstract

Section: B Covertnessmentioning

confidence: 64%

Section: B Covertnessmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Practical Route to Entanglement-Assisted Communication Over Noisy Bosonic Channels

2020

View full text Add to dashboard Cite

show abstract

“…The above condition on N S comes from Alice and Bob setting a requirement that the adversary's probability of error P e , in detecting their transmission attempt must satisfy, 1/2 ≥ P e ≥ 1/2 − δ. This dependence of N S on m ultimately leads to the square-root law of covert communications, i.e., O( √ m), but no more, bits can be transmitted reliably yet covertly [31,32].…”

Section: Define ρTh (α Nmentioning

confidence: 99%

Infinite-fold enhancement in communications capacity using pre-shared entanglement

Guha,

Zhuang,

Bash

2020

Preprint

Self Cite

View full text Add to dashboard Cite

Pre-shared entanglement can significantly boost communication rates in the regime of high thermal noise, and a low-brightness transmitter. In this regime, the ratio between the entanglementassisted capacity and the Holevo capacity, the maximum reliable-communication rate permitted by quantum mechanics without any pre-shared entanglement as a resource, is known to scale as log(1/NS), where NS 1 is the mean transmitted photon number per mode. This is especially promising in enabling a large boost to radio-frequency communications in the weak-transmit-power regime, by exploiting pre-shared optical-frequency entanglement, e.g., distributed by the quantum internet. In this paper, we propose a structured design of a quantum transmitter and receiver that leverages continuous-variable pre-shared entanglement from a downconversion source, which can harness this purported infinite-fold capacity enhancement-a problem open for over a decade. Finally, the implication of this result to the breaking of the well-known square-root law for covert communications, with pre-shared entanglement assistance, is discussed.

show abstract

Fundamental limits of quantum-secure covert communication over bosonic channels

Cited by 2 publications

References 0 publications

Practical Route to Entanglement-Assisted Communication Over Noisy Bosonic Channels

Practical Route to Entanglement-Assisted Communication Over Noisy Bosonic Channels

Infinite-fold enhancement in communications capacity using pre-shared entanglement

Contact Info

Product

Resources

About