13 papers
Relative-Entropy Geometry and Convergence in Nonconvex Wiretap Optimization
Farzin Salek, Masahito Hayashi
We develop and analyze an entropic descent method for a nonconvex optimization problem on probability simplices arising in classical and quantum secure communication. The optimizat…
From Symmetry to Secrecy: Covariant Classical--Quantum Wiretap Channels
Masahito Hayashi, Farzin Salek
For classical--quantum wiretap channels with a transitive covariant input action, both output ensembles admit a description as unitary group orbits of fixed seed states. We use thi…
Universality Sacrifices Reliability in Classical-Quantum Channel Coding
Kaito Watanabe, Masahito Hayashi, Takaya Matsuura +1
Universal channel coding enables communication without a complete description of the channel. For classical channels, universal codes can attain both capacity and the optimal high-…
Generalised quantum Stein's lemma more robust than ever
Filippo Girardi, Kuan-Yi Lee, Masahito Hayashi +1
The generalised quantum Stein's lemma is a key result in quantum hypothesis testing, and connects this fundamental primitive of quantum information processing with quantum resource…
Minimax games for quantum channel discrimination
Kun Fang, Michael X. Cao, Hao-Chung Cheng +2
Quantum channel discrimination is a primitive task for identifying, verifying, and benchmarking quantum dynamics. Previous studies have primarily considered either the best-case te…
Robust CHSH Self-Testing with Finite-Energy GKP States
Farzin Salek, Masahito Hayashi
We present a full-oscillator analysis of a finite-energy GKP CHSH test whose observed score yields robust Bell-pair self-testing. Periodically binned position and momentum give the…
Operational interpretation of the reverse sandwiched Renyi divergences in composite quantum hypothesis testing
Masahito Hayashi, Kun Fang
We study the Hoeffding regime of composite quantum hypothesis testing, in which each hypothesis is specified by a sequence of sets of quantum states. We establish quantum Hoeffding…
Adversarial Hypothesis Testing for Quantum Channels
Masahito Hayashi, Hao-Chung Cheng, Li Gao
This paper presents a systematic study of adversarial hypothesis testing for both quantum-quantum (QQ) and classical-quantum (CQ) channels. Unlike conventional channel discriminati…
Error exponents of quantum state discrimination with composite correlated hypotheses
Kun Fang, Masahito Hayashi
We study the error exponents in quantum hypothesis testing between two sets of quantum states, extending the analysis beyond the independent and identically distributed case to enc…
Resolvability of classical-quantum channels
Masahito Hayashi, Hao-Chung Cheng, Li Gao
Channel resolvability concerns the minimum resolution for approximating the channel output. We study the resolvability of classical-quantum channels in two settings, for the channe…
Bregman-divergence-based Arimoto-Blahut algorithm
Masahito Hayashi
We generalize the generalized Arimoto-Blahut algorithm to a general function defined over Bregman-divergence system. In existing methods, when linear constraints are imposed, each…
Three-Receiver Quantum Broadcast Channels: Classical Communication with Quantum Non-unique Decoding
Farzin Salek, Patrick Hayden, Masahito Hayashi
In network communication, it is common in broadcasting scenarios for there to exist a hierarchy among receivers based on information they decode due, for example, to different phys…
Reverse em-problem based on Bregman divergence and its application to classical and quantum information theory
Masahito Hayashi
The recent paper (IEEE Trans. IT 69, 1680) introduced an analytical method for calculating the channel capacity without the need for iteration. This method has certain limitations…