Quantum Channel State Masking

TL;DR

This paper investigates quantum communication over channels with state dependence, focusing on masking the channel state information from the decoder, and provides theoretical characterizations and bounds for capacity and leakage.

Contribution

It offers a full characterization of the entanglement-assisted masking equivocation region and derives bounds for quantum capacity-leakage functions in state-dependent channels.

Findings

Full characterization of entanglement-assisted masking equivocation region.

Regularized formula for quantum capacity-leakage without assistance.

Single-letter bounds for Hadamard channels that match in the standard case.

Abstract

Communication over a quantum channel that depends on a quantum state is considered when the encoder has channel side information (CSI) and is required to mask information on the quantum channel state from the decoder. A full characterization is established for the entanglement-assisted masking equivocation region, and a regularized formula is given for the quantum capacity-leakage function without assistance. For Hadamard channels without assistance, we derive single-letter inner and outer bounds, which coincide in the standard case of a channel that does not depend on a state.