# Classical-Quantum Arbitrarily Varying Wiretap Channel: Secret Message Transmission under Jamming Attacks

## TL;DR

This paper studies classical-quantum wiretap channels under simultaneous eavesdropping and jamming attacks, introducing stricter secrecy codes, analyzing capacity conditions, and exploring their discontinuity and super-activation phenomena.

## Contribution

It introduces a more stringent secrecy code class, proves capacity equality conditions, and characterizes the capacities' discontinuity and super-activation properties.

## Key findings

- Non-symmetrizability ensures capacity equality.
- Complete characterization of capacity discontinuity points.
- Identification of super-activation phenomena in capacities.

## Abstract

We analyze arbitrarily varying classical-quantum wiretap channels.These channels are subject to two attacks at the same time: one passive (eavesdropping), and one active (jamming). We progress on previous works by introducing a reduced class of allowed codes that fulfills a more stringent secrecy requirement than earlier definitions. In addition, we prove that non-symmetrizability of the legal link is suficient for equality of the deterministic and the common randomness assisted secrecy capacities. At last, we focus on analytic properties of both secrecy capacities: We completely characterize their discontinuity points, and their super-activation properties.