FR2.R1.2

Resource-Efficient Entanglement-Assisted Covert Communications over Bosonic Channels

Shi-Yuan Wang, Shang-Jen Su, Matthieu Bloch, Georgia Institute of Technology, United States

Session:
Quantum Cryptography

Track:
6: Quantum Information and Coding Theory

Location:
Ballroom II & III

Presentation Time:
Fri, 12 Jul, 11:50 - 12:10

Session Chair:
Matthieu Bloch,
Abstract
We revisit the problem of entanglement-assisted covert communication over bosonic channels and show that the benefits of entanglement can be achieved with fewer entanglement resources than previously identified. Specifically, we show that $\calO(\sqrt{n}\log n)$ covert and reliable bits can be exchanged using $\omega(\sqrt{n})\cap o(n)$ Two-Mode Squeezed-Vacuum (TMSV) pairs and $\omega(1)\cap o(\sqrt{n})$ secret-key bits. The conceptual approach behind the result is to combine 1) soft-covering and secret-key resources as a coordination mechanism and 2) superposition coding in the form of a two-layer On-Off Keying (OOK) and Phase Shift Keying (PSK) to index channel uses in which TMSV pairs are encoded. This approach is related to the idea of quantum trade-off coding, specialized and extended to the covert communication setting. Our technical contribution is to develop one-shot bounds then specialized to bosonic channels.
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