Researcher Database

WATANABE Shun

■Faculty	Institute of Engineering　Division of Electrical Engineering and Computer Science
■Position	Associate Professor

Last Updated :2026/07/29

Activity information

Name and contact details

Name
ワタナベ　シユン, 渡辺　峻, WATANABE Shun

Affiliation / Position

Institute of Engineering　Division of Electrical Engineering and Computer Science, Associate Professor

Other affiliation

Faculty of Engineering　Department of Computer and Information Sciences

Graduate School of Engineering　Department of Computer and Information Sciences

Current state of research and teaching activities

Information theory, Communication Engineering Cryptography,Information security

Grants-in-Aid for Scientific Research

基盤研究（A）
情報・計算・暗号の融合によるセキュリティ定量化基盤の構築
From 2024, To 2024

基盤研究（A）
情報・計算・暗号の融合によるセキュリティ定量化基盤の構築
From 2023, To 2023

挑戦的研究（開拓）
セキュリティ解析の新理論～情報量不等式から計算量不等式へ～
From 2023, To 2025

基盤研究(B)
IoT社会の高度化に必要な多端子情報理論と暗号理論を柱とした安全通信理論の構築
From 2022, To 2022

基盤研究(B)
IoT社会の高度化に必要な多端子情報理論と暗号理論を柱とした安全通信理論の構築
From 2021, To 2021

基盤研究(B)
生体認証技術を見据えたセキュアな分散検定理論の構築
From 2020, To 2023

基盤研究(B)
IoT社会の高度化に必要な多端子情報理論と暗号理論を柱とした安全通信理論の構築
From 2020, To 2020

基盤研究(B)
IoT社会の高度化に必要な多端子情報理論と暗号理論を柱とした安全通信理論の構築
From 2019, To 2019

基盤研究(B)
IoT社会の高度化に必要な多端子情報理論と暗号理論を柱とした安全通信理論の構築
From 2018, To 2018

若手研究(A)
双方向通信を伴う分散計算のための情報理論の展開
From 2016, To 2019

研究活動スタート支援
双方向通信を伴う分散計算における情報理論的解析手法の構築
From 2015, To 2016

基盤研究（A）
情報・計算・暗号の融合によるセキュリティ定量化基盤の構築
From 2025, To 2025

Papers

An Improved Lower Bound on Oblivious Transfer Capacity via Interactive Erasure Emulation
So Suda, Shun Watanabe, Haruya Yamaguchi
Proceedings of International Symposium on Information Theory 2024
IEEE
07 Jul. 2024, Research paper (international conference proceedings), joint, DOI(公開)(r-map)

Geometric Aspects of Data Processing of Markov Chains
Geoffrey Wolfer, Shun Watanabe
Transactions of Mathematics and Its Applications
19 May 2024, Research paper (scientific journal), joint, 8, 1, DOI(公開)(r-map)

Bit-Security Preserving Hardness Amplification
Shun Watanabe, Kenji Yasunaga
Proceedings of Theory of Cryptography Conference 2024
Springer
28 Nov. 2024, Research paper (international conference proceedings), joint, DOI(公開)(r-map)

Unified View for Notions of Bit Security
Shun Watanabe, Kenji Yasunaga
Proceedings of ASIACRYPT 2023
Springer
Dec. 2023, Research paper (international conference proceedings), joint, DOI(公開)(r-map)

Information geometry of Markov Kernels: a survey
Wolfer, Geoffrey; Watanabe, Shun
FRONTIERS IN PHYSICS
FRONTIERS MEDIA SA
Information geometry and Markov chains are two powerful tools used in modern fields such as finance, physics, computer science, and epidemiology. In this survey, we explore their intersection, focusing on the theoretical framework. We attempt to provide a self-contained treatment of the foundations without requiring a solid background in differential geometry. We present the core concepts of information geometry of Markov chains, including information projections and the pivotal information geometric construction of Nagaoka. We then delve into recent advances in the field, such as geometric structures arising from time reversibility, lumpability of Markov chains, or tree models. Finally, we highlight practical applications of this framework, such as parameter estimation, hypothesis testing, large deviation theory, and the maximum entropy principle.
27 Jul. 2023, Research paper (scientific journal), joint, 11, 2296-424X, DOI(公開)(r-map)

Tight Exponential Strong Converse for Source Coding Problem with Encoded Side Information
Daisuke Takeuchi, Shun Watanabe
Proceedings of 2023 IEEE International Symposium on Information Theory
IEEE
Jul. 2023, Research paper (international conference proceedings), joint, DOI(公開)(r-map)

Complete Characterization of Broadcast and Pseudo-Signatures from Correlations
Varun Narayanan, Vinod M. Prabhakaran, Neha Sangwan, Shun Watanabe
Proceedings of EUROCRYPT 2023
Springer
May 2023, Research paper (international conference proceedings), joint, DOI(公開)(r-map)

On Sub-optimality of Random Binning for Distributed Hypothesis Testing
Shun Watanabe
Proceedings of 2023 IEEE International Symposium on Information Theory
26 Jun. 2022, Research paper (international conference proceedings), only, DOI(公開)(r-map)

Minimax Converse for Identification via Channels
Shun Watanabe
IEEE Transactions on Information Theory
IEEE
01 Jan. 2022, Research paper (scientific journal), only, 68, 1, DOI(公開)(r-map), 25, 34

Bit Security as Computational Cost for Winning Games with High Probability
Shun Watanabe and Kenji Yasunaga
Proc. ASIACRYPT 2021
Springer
01 Dec. 2021, Research paper (international conference proceedings), joint, DOI(公開)(r-map)

Information Geometry of Reversible Markov Chains
Geoffrey Wolfer and Shun Watanabe
Information Geometry
Springer
22 Nov. 2021, Research paper (scientific journal), joint, 4, DOI(公開)(r-map), 393, 433

The Achievable Rate Region of Wyner-Ahlswede-Körner Coding Problem for Mixed Sources
Daisuke Takeuchi and Shun Watanabe
Proc. 2021 IEEE Information Theory Workshop (ITW)
IEEE
17 Oct. 2021, Research paper (international conference proceedings), joint, DOI(公開)(r-map)

A Classification of Functions in Multiterminal Distributed Computing
Shun Watanabe
Transactions on Information Theory
IEEE
01 Oct. 2020, Research paper (scientific journal), only, 66, 10, DOI(公開)(r-map), 6169, 6183

Finite-Length Analyses for Source and Channel Coding on Markov Chains
Masahito Hayashi, Shun Watanabe
Entropy
MDPI
18 Apr. 2020, Research paper (scientific journal), joint, 22, 4, DOI(公開)(r-map)

Interval Algorithm for Random Number Generation: Information Spectrum Approach
Shun Watanabe, Te Sun Han
Transactions on Information Theory
IEEE
01 Mar. 2020, Research paper (scientific journal), joint, 66, 3, DOI(公開)(r-map), 1691, 1701

Strong Converse using Change of Measure Arguments
Himanshu Tyagi, Shun Watanabe
Transactions on Information Theory
IEEE
01 Feb. 2020, Research paper (scientific journal), joint, 66, 2, DOI(公開)(r-map), 689, 703

Communication for Generating Correlation: A Unifying Survey
Madhu Sudan, Himanshu Tyagi, Shun Watanabe
Transactions on Information Theory
IEEE
01 Jan. 2020, Research paper (scientific journal), joint, 66, 1, DOI(公開)(r-map), 5, 37

Neyman-Pearson Test for Zero-Rate Multiterminal Hypothesis Testing
Watanabe, Shun
IEEE TRANSACTIONS ON INFORMATION THEORY
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
The problem of zero-rate multiterminal hypothesis testing is revisited from the perspective of information-spectrum approach and finite blocklength analysis. A Neyman-Pearson-like test is proposed and its non-asymptotic performance is clarified, for a short block length, it is numerically determined that the proposed test is superior to the previously reported Hoeffdinglike test proposed by Han-Kobayashi. For a large deviation regime, it is shown that our proposed test achieves an optimal trade-off between the type I and type II exponents presented by Han-Kobayashi. Among the class of symmetric (type-based) testing schemes, when the type I error probability is non-vanishing, the proposed test is optimal up to the second-order term of the type II error exponent; the latter term is characterized in terms of the variance of the projected relative entropy density. The information geometry method plays an important role in the analysis as well as the construction of the test.
Jul. 2018, Research paper (international conference proceedings), only, 64, 7, 0018-9448, DOI(公開)(r-map), 4923, 4939

Interactive Communication for Data Exchange
Tyagi, Himanshu; Viswanath, Pramod; Watanabe, Shun
IEEE TRANSACTIONS ON INFORMATION THEORY
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Two parties observing correlated data seek to exchange their data using interactive communication. How many bits must they communicate? We propose a new interactive protocol for data exchange, which increases the communication size in steps until the task is done. We also derive a lower bound on the minimum number of bits that is based on relating the data exchange problem to the secret key agreement problem. Our single-shot analysis applies to all discrete random variables and yields upper and lower bounds of a similar form. In fact, the bounds are asymptotically tight and lead to a characterization of the optimal rate of communication needed for data exchange for a general source sequence, such as a mixture of independent and identically distributed (IID) random variables as well as the optimal second-order asymptotic term in the length of communication needed for data exchange for IID random variables, when the probability of error is fixed. This gives a precise characterization of the asymptotic reduction in the length of optimal communication due to interaction; in particular, two-sided Slepian-Wolf compression is strictly suboptimal.
Jan. 2018, Research paper (scientific journal), joint, 64, 1, 0018-9448, DOI(公開)(r-map), 26, 37

On Distributed Computing for Functions with Certain Structures
Shigeaki Kuzuoka and Shun Watanabe
IEEE Transactions on Information Theory
Nov. 2017, Research paper (scientific journal), joint, 63, 11, DOI(公開)(r-map), 7003, 7017

Information Complexity Density and Simulation of Protocols
Himanshu Tyagi, Shaileshh Venkatakrishnan, Pramod Viswanath, and Shun Watanabe
IEEE Transactions on Information Theory
Nov. 2017, Research paper (scientific journal), joint, 63, 11, DOI(公開)(r-map), 6979, 7002

Universal Multiparty Data Exchange and Secret Key Agreement
Himanshu Tyagi and Shun Watanabe
IEEE Transactions on Information Theory
Jul. 2017, Research paper (scientific journal), joint, 63, 11, DOI(公開)(r-map), 4057, 4074

Second-Order Region for Gray-Wyner Network
Watanabe, Shun
IEEE TRANSACTIONS ON INFORMATION THEORY
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
The coding problem over the Gray-Wyner network is studied from the second-order coding rates perspective. A tilted information density for this network is introduced in the spirit of Kostina-Verdu, and, under a certain regularity condition, the second-order region is characterized in terms of the variance of this tilted information density and the tangent vector of the first-order region. The second-order region is proved by the type method: the achievability part is proved by the type-covering argument, and the converse part is proved by a refinement of the perturbation approach that was used by Gu-Effros to show the strong converse of the Gray-Wyner network. This is the first instance that the second-order region is characterized for a multi-terminal problem, where the characterization of the first-order region involves an auxiliary random variable.
Feb. 2017, Research paper (scientific journal), only, 63, 2, 0018-9448, DOI(公開)(r-map), 1006, 1018

Channel Simulation and Coded Source Compression
Min-Hsiu Hsieh and Shun Watanabe
IEEE Transactions on Information Theory
Nov. 2016, Research paper (scientific journal), joint, 62, 11, DOI(公開)(r-map), 6609, 6619

Secret Key Agreement: General Capacity and Second-Order Asymptotics
Masahito Hayashi, Himanshu Tyagi, and Shun Watanabe
IEEE Transactions on Information Theory
Jul. 2016, Research paper (scientific journal), joint, 62, 7, DOI(公開)(r-map), 3796, 3810

Uniform Random Number Generation from Markov Chains: Non-Asymptotic and Asymptotic Analyses
Masahito Hayashi and Shun Watanabe
IEEE Transactions on Information Theory
Apr. 2016, Research paper (scientific journal), joint, 62, 4, DOI(公開)(r-map), 3796, 3810

Information Geometry Approach to Parameter Estimation in Markov Chains
Masahito Hayashi and Shun Watanabe
Annals of Statistics
Apr. 2016, Research paper (scientific journal), joint, 44, 4, 1495, 1535

Presentations

Information Theoretic Cryptography
Distinguished lecture at Sun Yat-Sen University
Dec. 2023, Public discourse, seminar, tutorial, course, lecture and others

On Sub-optimality of Random Binning for Distributed Hypothesis Testing
the Oberwolfach Workshop New Mathematical Techniques in Information Theory
15 Mar. 2022, Oral presentation(invited, special)

Isomorphism Problem Revisited: Information Spectrum Approach
IEEE International Symposium on Information Theory
21 Jun. 2020, Oral presentation(general)

Random Number Generation: Old and New
2019 Workshop on Probability and Information Theory
19 Aug. 2019, Oral presentation(invited, special)

Tutorial on Information Theoretic Cryptography
Croucher Summer Course on Information Theory (Hong Kong)
22 Jul. 2019, Oral presentation(invited, special)

Strong Converse using Change of Measure Arguments
2018 IEEE International Symposium on Information Theory
17 Jul. 2019, Oral presentation(general)

A New Proof of Nonsignalling Multiprover Parallel Repetition Theorem
2019 IEEE International Symposium on Information Theory
01 Jul. 2019, Oral presentation(general)

Change of Measure Argument for Strong Converse and Application to Parallel Repetition Theorem
Fifth London Symposium on Information Theory 2019
30 May 2019, Oral presentation(invited, special)

A Classification of Functions in Multiterminal Distributed Computing
2018 IEEE International Symposium on Information Theory
17 Jul. 2018, Oral presentation(general)

Proving Strong Converse is Di cult?
International Conference on Signal Processing and Communications
16 Jul. 2018, Oral presentation(invited, special)

Neyman-Pearson Test and Hoe ding Test
Bombay Information Theory Seminar
13 Jan. 2018, Oral presentation(invited, special)

A Converse Bound on Wyner-Ahlswede-Korner Network via Gray-Wyner Network
2017 IEEE Information Theory Workshop
07 Nov. 2017, Oral presentation(general)

Neyman-Pearson Test for Zero-Rate Multiterminal Hypothesis Testing
2017 IEEE International Symposium on Information Theory
26 Jun. 2017, Oral presentation(general)

Optimality of The Recursive Data Exchange Protocol
2017 IEEE International Symposium on Information Theory
26 Jun. 2017, Oral presentation(general)

Information Theoretic Cryptography for Information Theorists
2017 IEEE International Symposium on Information Theory
25 Jun. 2017, Other

On Distributed Computing for Functions with Certain Structures
2016 IEEE Information Theory Workshop
10 Sep. 2016, Oral presentation(general)

Converse to Wiretap Channel Coding
Beyond IID Workshop 2016
10 Jul. 2016, Oral presentation(invited, special)

Universal Multiparty Data Exchange
2016 IEEE International Symposium on Information Theory
01 Jul. 2016, Oral presentation(general)

Sensitivity of Functions and Distributed Coding
SPCOM 2016
10 Jun. 2016, Oral presentation(invited, special)

Information Theoretic Secrecy and Interactive Communication
Workshop on Nexus of Information and Computation Theories
20 Mar. 2016, Oral presentation(invited, special)

Committee Memberships

Chinese University of Hong Kong
External Examiner for Ph. D Degree
From 20200601, To 20200701

National Tsing Hua University
External reviewer for a hiring committee
From 20200101, To 20201031

IEEE
General Co-Chair of 2021 Information Theory Workshop
From 20190301, To 20211031

IEEE
Associate Editor of Transactions on Information Theory
From 20160801, To 20200731