Simultaneous transmission of classical and quantum information under channel uncertainty and jamming attacks

TL;DR

This paper develops universal coding strategies for the simultaneous transmission of classical information and entanglement over quantum channels, even under malicious attacks and channel uncertainties, establishing optimal capacity characterizations.

Contribution

It introduces universal codes robust to channel uncertainty and malicious jamming, extending capacity characterizations for compound and arbitrarily varying quantum channels.

Findings

Universal codes for classical and quantum info transmission under attack.

Multi-letter capacity region characterizations.

Dichotomy results for different jammer capabilities.

Abstract

We derive universal codes for simultaneous transmission of classical messages and entanglement through quantum channels, possibly under attack of a malignant third party. These codes are robust to different kinds of channel uncertainty. To construct such universal codes, we invoke and generalize properties of random codes for classical and quantum message transmission through quantum channels. We show these codes to be optimal by giving a multi-letter characterization of regions corresponding to the capacity of compound quantum channels for simultaneously transmitting and generating entanglement with classical messages. Also, we give dichotomy statements in which we characterize the capacity of arbitrarily varying quantum channels for simultaneous transmission of classical messages and entanglement. These include cases where the malignant jammer present in the arbitrarily varying channel model is classical (chooses channel states of product form) and fully quantum (is capable of general attacks not necessarily of product form).