Quantum channel discrimination against jammers

IEEE International Symposium on Information Theory (ISIT), pp. 1–6

Abstract

We study the problem of quantum channel discrimination between two channels with an adversary input party (a.k.a. a jammer). This setup interpolates between the best-case channel discrimination as studied by (Wang & Wilde, 2019) and the worst-case channel discrimination as studied by (Fang, Fawzi, & Fawzi, 2025), thereby generalizing both frameworks. To address this problem, we introduce the notion of minimax channel divergence and establish several of its key mathematical properties. We prove the Stein's lemma in this new setting, showing that the optimal type-II error exponent in the asymptotic regime under parallel strategies is characterized by the regularized minimax channel divergence.

Authors 2

1. Kun Fang

   Chinese University of Hong Kong

   Affiliation as printed

   CUHK-Shenzhen

2. Michael X. Cao Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen