activity
20242026
collaborators

7 papers

cs.IT2026

Two-Way Wiretap Channel under Mixed Secrecy Constraint

Yanling Chen, Masahito Hayashi

This paper studies the two-way wiretap channel (TW-WC) with an external eavesdropper under strong one-sided (mixed) secrecy: only User~1's message is required to be secure from the…

quant-ph2025

Measuring quantum relative entropy with finite-size effect

Masahito Hayashi

We study the estimation of relative entropy when is known. We show that the Cramér-Rao type bound equals the relative varentropy. Our estimator attains the Cramé…

quant-ph2025

Heisenberg scaling based on population coding

Masahito Hayashi

We study Heisenberg scaling of quantum metrology in the viewpoint of population coding. Although Fisher information has been used for a figure of merit to characterize Heisenberg s…

quant-ph2025

Application of -order Information Metrics for Secure Communication in Quantum Physical Layer Design

Masahito Hayashi, Angeles Vázquez-Castro

Quantum physical layer security protocols offer significant advantages, particularly in space communications, but their achievable secrecy rates are often limited to the asymptotic…

quant-ph2025

Entanglement measures for detectability

Masahito Hayashi, Yuki Ito

We propose new entanglement measures as the detection performance based on the hypothesis testing setting. We clarify how our measures work for detecting an entangled state by exte…

quant-ph2024

Asymmetry activation and its relation to coherence under permutation operation

Masahito Hayashi

A Dicke state and its decohered state are invariant for permutation. However, when another qubits state to each of them is attached, the whole state is not invariant for permutatio…