Shun Watanabe's Homepage

Shun Watanabe

Associate Professor

Department of Computer and Information Sciences

Tokyo University of Agriculture and Technology, Japan

Email: shunwata [at] cc.tuat.ac.jp

Phone: +81-42-388-7896

YouTube channel

Biography:

Shun Watanabe received B.E., M.E., and Ph.D. degree from Tokyo Institute of Technology

in 2005, 2007, and 2009, respectively. During April 2009 to February 2015, he was an assistant professor of

the Department of Information Science and Intelligence Systems at the University of Tokushima. 

During April 2013 to March 2015, he was a visiting assistant professor of the Institute for Systems Research

at the University of Maryland, College Park. During March to April 2016, he was a visiting fellow 

at the Institute of Henri Poincare. Since February 2015, he has been an associate professor

of the Department of Computer and Information Sciences at Tokyo University of Agriculture and Technology.

He is a senior member of IEEE and a member of IEICE.  During 2016 to 2020, he served as an Associate Editor 

for the IEEE Transactions on Information Theory. He served as a general co-chair of the 2021 IEEE Information Theory Workshop. 

During 2022-2024, he was a Board of Governor of IEEE Information Theory Society. He was an IEEE IT Society Distinguished Lecturer for 2023-2024.

Research Interests:

Information theory, Cryptography, Quantum information, Information geometry

Open positions:

I am looking for graduate students and postdoc fellows. 

Please feel free to contact me if you are interested in working with me.

For students pursuing Ph. D degree, financial support is available from MEXT Japan.

For postdoc fellows, financial support is available from JSPS.

Publications:

Our book (with Himanshu Tyagi) on "information-theoretic cryptography" has been published from Cambridge University Press (publisher site, Amazon).

overview video;  list of errata.

Recent work:

1. "Combinatorial Characterization of Exponential Families of Lumpable Stochastic Matrices," (with Geoffrey Wolfer).

2. "Bit-Security Preserving Hardness Amplification," TCC 2024 (with Kenji Yasunaga).

3. "An Improved Lower Bound on Oblivious Transfer Capacity Using Polarization and Interaction," (with So Suda).

4. "Channel Resolvability Using Multiplicative Weight Update Algorithm," (with Koki Takahashi).

5. "Tight Exponential Strong Converse for Lossy Source Coding with Side-Information and Distributed Function Computation." 

Journal Papers:

1. "Tight Exponential Strong Converse for Source Coding with Encoded Side Information," IEEE Transactions on Information Theory, vol. 71, no. 3, pp. 1533-1545, March 2025 (with Daisuke Takeuchi).

2. "Geometric Aspects of Data Processing of Markov Chains," Transactions of Mathematics and Its Applications, vol. 8, no. 1, May 2024 (with Geoffrey Wolfer).

3. "Information geometry of Markov kernels: a survey," Frontiers in Physics, vol. 11, 1195562, July 2023 (with Geoffrey Wolfer).

4. "Minimax Converse for Identification via Channels,"  IEEE Transactions on Information Theory, vol. 68, no. 1, pp. 25-34, January 2022.

5. "Information Geometry of Reversible Markov Chains," Information Geometry, November 2021 (with Geoffrey Wolfer).

6. "A Classification of Functions in Multiterminal Distributed Computing," IEEE Transactions on Information Theory, vol. 66, no. 10, pp. 6169-6183, October 2020. 

7. "Finite-Length Analysis for Source and Channel Coding on Markov Chains," Entropy, vol 22, no. 4, p. 460, April 2020 (with Masahito Hayashi).

8. "Interval Algorithm for Random Number Generation: Information Spectrum Approach," IEEE Transactions on Information Theory, vol. 66, no. 3, pp. 1691-1701, March 2020 (with Te Sun Han).

9. "Strong Converse using Change of Measure Arguments," IEEE Transactions on Information Theory, vol. 66, no. 2, pp. 689-703, February 2020 (with Himanshu Tyagi).

10. "Communication for Generating Correlation: A Unifying Survey," IEEE Transactions on Information Theory, vol. 66, no. 1, pp. 5-37, January 2020 (with Madhu Sudan and Himanshu Tyagi).

11. "Neyman-Pearson Test for Zero-Rate Multiterminal Hypothesis Testing," IEEE Transactions on Information Theory, vol. 64, no. 7, pp. 4923-4939, July 2018.

12. "Interactive Communication for Data Exchange," IEEE Transactions on Information Theory, vol. 64, no. 1, pp. 26-37, January 2018 (with Himanshu Tyagi and Pramod Viswanath).

13. "On Distributed Computing for Functions with Certain Structures," IEEE Transactions on Information Theory, vol. 63, no. 11, pp. 7003-7017, November 2017 (with Shigeaki Kuzuoka).

14. "Information Complexity Density and Simulation of Protocols," IEEE Transactions on Information Theory, vol. 63, no. 11, pp. 6979-7002, November 2017 (with Himanshu Tyagi, Shaileshh Venkatakrishnan, and Pramod Viswanath). 

15. "Universal Multiparty Data Exchange and Secret Key Agreement," IEEE Transactions on Information Theory, vol. 63, no. 7, pp. 4057-4074, July 2017 (with Himanshu Tyagi).

16. "Second-Order Region for Gray-Wyner Network," IEEE Transactions on Information Theory, vol. 63, no. 2, pp. 1006-1018, February 2017.

17. "Finite-length Analysis on Tail probability for Markov Chain and Application to Simple Hypothesis Testing," Annals of Applied Probability, vol. 27, no. 2, pp. 811-845, 2017 (with Masahito Hayashi).

18. "Channel Simulation and Coded Source Compression," IEEE Transactions on Information Theory, vol. 62, no. 11, pp. 6609-6619, November 2016 (with Min-Hsiu Hsieh).

19. "Secret Key Agreement: General Capacity and Second-Order Asymptotics," IEEE Transactions on Information Theory, vol. 62, no. 7, pp. 3796-3810, July 2016 (with Masahito Hayashi and Himanshu Tyagi).

20. "Uniform Random Number Generation from Markov Chains: Non-Asymptotic and Asymptotic Analyses," IEEE Transactions on Information Theory, vol. 62, no. 4, pp. 1795-1822, April 2016 (with Masahito Hayashi).

21. "Information Geometry Approach to Parameter Estimation in Markov Chains," Annals of Statistics, vol. 44, no. 4, pp. 1495-1535, 2016 (with Masahito Hayashi).

22. "A Dichotomy of Functions in Distributed Coding: An Information Spectral Approach," IEEE Transactions on Information Theory, vol. 61, no. 9, pp. 5028-5041, September 2015 (with Shigeaki Kuzuoka).

23. "Converses for Secret Key Agreement and Secure Computing," IEEE Transactions on Information Theory, vol. 61, no. 9, pp. 4809-4827, September 2015 (with Himanshu Tyagi).

24. "An Information-Spectrum Approach to Weak Variable-Length Source Coding with Side-Information," IEEE Transactions on Information Theory, vol. 61, no. 6, pp. 3559-3573, June 2015 (with Shigeaki Kuzuoka).

25. "Non-Asymtptic and Second Order Achievability Bounds for Coding with Side-Information," IEEE Transactions on Information Theory, vol. 61, no. 4, pp. 1574-1605, April 2015 (with Shigeaki Kuzuoka and Vincent Y. F. Tan).

26. "The Optimal Use of Rate-Limited Randomness in Broadcast Channels with Confidential Messages," IEEE Transactions on Information Theory, vol. 61, no. 2, pp. 983-995, February 2015 (with Yasutada Oohama).

27. "Cognitive Interference Channels with Confidential Messages under Randomness Constraint," IEEE Transactions on Information Theory, vol. 60, no. 12, pp. 7698-7707, December 2014 (with Yasutada Oohama).

28. "Universal Wyner-Ziv Coding for Distortion Constrained General Side-Information," IEEE Transactions on Information Theory, vol. 60, no. 12, pp. 7568-7583, December 2014 (with Shigeaki Kuzuoka).

29. "Optimal Axis Compensation in Quantum Key Distribution Protocols over Unital Channels," Theoretical Computer Science:, Elsevier, vol. 560, part 1, Theoretical Aspect of Quantum Cryptography--Celebrating 30 years of BB84, pp. 91-106, December 2014 (with Ryutaroh Matsumoto and Tomohiko Uyematsu).

30. "The Rate-Distortion Function for Product of Two Sources with Side-Information at Decoders," IEEE Transactions on Information Theory, vol. 59, no. 9, pp. 5678-5691, September 2013.

31. "Private and Quantum Capacities of More Capable and Less Noisy Quantum Channels," Physical Review A, vol. 85, no. 1, p. 012326, January 2012.

32. "Secret Key Agreement from Vector Gaussian Sources by Rate Limited Public Communication," IEEE Transactions on Information Forensics and Security, vol. 6, no. 3, pp. 541-550, September 2011 (with Yasutada Oohama).

33. "Secret Key Agreement from Correlated Gaussian Sources by Rate Limited Public Communication," IEICE Transactions on Fundamentals, vol. E93, no. 11, pp. 1976-1983, November 2010 (with Yasutada Oohama).

34. "Strongly Secure Privacy Amplification Cannot Be Obtained by Encoder of Slepian-Wolf Code," IEICE Transactions on Fundamentals, vol. E93, no. 9, pp. 1650-1659, September 2010 (with Ryutaroh Matsumoto and Tomohiko Uyematsu).

35. "Narrow basis angle doubles secret key in the BB84 protocol," Journal of Physics A: Mathematical and Theoretical, vol. 43, no. 14, p. 145302, April 2010 (with Ryutaroh Matsumoto).

36. "Universal Source Coding over Generalized Complementary Delivery Networks," IEEE Transactions on Information Theory, vol. 55, no. 3, pp. 1360-1373, March 2009 (with Akisato Kimura, Tomohiko Uyematsu, and Shigeaki Kuzuoka).

37. "Secret Key Agreement by Soft-Decsion of Signals in Gaussian Maurer's Model," IEICE Transactions on Fundamentals, vol. E92, no. 2, pp. 525-534, February 2009 (with Masashi Naito, Ryutaroh Matsumoto, and Tomohiko Uyematsu).

38. "Tomography Increases Key Rates of Quantum Key Distribution Protocols," Physical Review A, vol. 78, no. 4, p. 042316, October 2008 (with Ryutaroh Matsumoto and Tomohiko Uyematsu).

39. "Key Rate Available from Mismatched Measurements in the BB84 Protocol and the Uncertainty Principle," IEICE Transactions on Fundamentals., vol. E91, no. 10, pp. 2870-2873, October 2008 (with Ryutaroh Matsumoto).

40. "Key Rate of Quantum Key Distribution with Hashed Two-Way Classical Communication," Physical Review A, vol. 76, no. 3, p. 032312, September 2007 (with Ryutaroh Matsumoto, Tomohiko Uyematsu, and Yasuhito Kawano).

41. "Noise Tolerance of the BB84 Protocol with Random Privacy Amplification," International Journal of Quantum Information, vol. 4, no. 6, pp. 935-946, December 2006 (with Ryutaroh Matsumoto and Tomohiko Uyematsu).

42. "Improvement of Stabilizer-Based Entanglement Distillation Protocols by Encoding Operators," Journal of Physics A: Mathematical and General, vol. 39, no. 16, pp. 4273-4290, April 2006 (with Ryutaroh Matsumoto and Tomohiko Uyematsu).

Others (some of talk slides, videos, etc.):

• • "Information Geometry of Markov Kernels," a seminar at Ben Gurion University (online), 2022. slide

  • "On Sub-optimality of Random Binning for Distributed Hypothesis Testing," a talk at Oberwolfach Workshop, 2022. slide

  • "Minimax Converse for Identification via Channels," a seminar at Technical University of Munich (online), 2021. slide

  • "Revisiting Identification and Common Randomness," a seminar at University of Maryland (online), 2020, video, board. 

  • "Random Number Generation: Old and New," a talk at Workshop on Probability and Information, 2019, slide.

  • "Change of Measure Argument for Strong Converse and Application to Parallel Repetition Theorem," a talk at London Symposium on Information Theory (LSIT 2019), video, slide.

  • "Function Structures and Distributed Computing," a seminar at Imperial College London, 2019, slide.

  • "Neyman-Pearson Test and Hoeffding Test," a talk at Bombay Information Theory Seminar (BITS 2018), video, slide. 

  • "Information Theoretic Cryptography for Information Theorists," Notes and Slides of a tutorial at ISIT 2017; see also an article in IT Society Newsletter (with Himanshu Tyagi).

  • "Second-Order Analysis for Multiterminal Networks," a seminar at Chinese University of Hong Kong, 2016, slide.

  • "Information Theoretic Secrecy and Interactive Communication," a tutorial at Nexus of Information and Computation Theories, Institute of Henri Poincare, 2016, videos: part 1, part 2, part 3 (with Himanshu Tyagi; I lectured the latter half of part 2 and part 3). 

  • "Secret Key Agreement: General Capacity and Second-Order Asymptotics," a talk at Mathematical Tools of Information-Theoretic Security Workshop, 2015, slide.

Conference and Workshop Papers (partial list):

1. "An Improved Lower Bound on Oblivious Transfer Capacity via Interactive Erasure Emulation," ISIT 2024 (with So Suda and Haruya Yamaguchi).

2. "Exponential Strong Converse in Multi-user Problems," International Zurich Seminar on Information and Communication (IZS) 2024.

3. "Unified View for Notions of Bit Security," AISACRYPT 2023, (with Kenji Yasunaga).

4. "A Geometric Reduction Approach for Identity Testing of Reversible Markov Chains," Geometric Science of Information (GSI'23), (with Geoffrey Wolfer).

5. "Complete Characterization of Broadcast and Pseudo-Signatures from Correlations," EUROCRYPT 2023, (with Varun Narayanan, Vinod M. Prabhakaran, and Neha Sangwan).

6. "A Numerical Study of Multi-letter Ahlswede-Han Scheme for Modulo-Sum Problem," ISITA 2022 (with Takuto Kakishima).

7. "On Sub-optimality of Random Binning for Distributed Hypothesis Testing," ISIT 2022.

8. "Bit Security as Computational Cost for Winning Games with High Probability," ASIACRYPT 2021 (with Kenji Yasunaga). 

9. "The Achievable Rate Region of Wyner-Ahlswede-Körner Coding Problem for Mixed Sources," ITW 2021 (with Daisuke Takeuchi). 

10. "Isomorphism Problem Revisited: Information Spectrum Approach," ISIT 2020, LA (with Te Sun Han). slide, video

11. "A New Proof of Nonsignaling Multiprover Parallel Repetition Theorem," ISIT 2019, Paris (with Himanshu Tyagi).

12. "Second-Order Optimal Test in Composite Hypothesis Testing," ISITA 2018, Singapore. pdf, slide

13. "A Converse Bound on Wyner-Ahlswede-Körner Network via Gray-Wyner Network," ITW 2017.

14. "Optimality of Recursive Data Exchange Protocol," ISIT 2017, Aachen (with Himanshu Tyagi).

15. "Information Complexity Density and Simulation of Protocols," ITCS 2016 (with Himanshu Tyagi, Shaileshh Venkatakrishnan, and Pramod Viswanath). 

16. "Fully Quantum Source Compression with a Quantum Helper," ITW 2015, Jeju (with Min-Hsiu Hsieh).

17. "Interactive Communication for Data Exchange," ISIT 2015, Hong Kong (with Himanshu Tyagi and Pramod Viswanath).

18. "Common Randomness for Secure Computing," ISIT 2015, Hong Kong (with Prakash Narayan and Himanshu Tyagi).

19. "Source Compression with a Quantum Helper," ISIT 2015, Hong Kong (with Min-Hsiu Hsieh).

20. "Converse Results for Secrecy Generation over Channels," Ailomar Conference 2014 (with Himanshu Tyagi).

21. "Strong Converse for a Degraded Wiretap Channel via Active Hypothesis Testing," Allerton 2014 (with Masahito Hayashi and Himanshu Tyagi).

22. "Strong Converse and Second-Order Asymptotics of Channel Resolvability," ISIT 2014, Honolulu, HI (extended version), (with Masahito Hayashi). 

23. "Secret key agreement: general capacity and second-order asymptotics," ISIT 2014, Honolulu, HI (with Masahito Hayashi and Himanshu Tyagi).

24. "Information Geometry Approach to Parameter Estimation in Markov Chains," ISIT 2014, Honolulu, HI (with Masahito Hayashi).

25. "An Information-Spectrum Approach to Weak Variable-Length Slepian-Wolf Coding," ISIT 2014, Honolulu, HI (with Shigeaki Kuzuoka).

26. "Moderate Deviations for Joint Source-Channel Coding of Systems With Markovian Memory," ISIT 2014, Honolulu, HI (with Vincent Y. F. Tan and Masahito Hayashi).

27. "A Bound for Multiparty Secret Key Agreement and Implications for A Problem of Secure Computing," EUROCRYPT 2014, Copenhagen, Denmark (with Himanshu Tyagi).

28. "Non-Asymptotic Bounds on Fixed Length Source Coding for Markov Chains," Allerton 2013 (with Masahito Hayashi).

29. "Secret Key Capacity For Multipleaccess Channel With Public Feedback," Allerton 2013 (with Himanshu Tyagi).

30. "Non-Asymptotic Analysis of Privacy Amplification via Renyi Entropy and Inf-Spectral Entropy," ISIT 2013, Istanbul, Turkey (extended version), (with Masahito Hayashi).

31. "Cognitive Interference Channels with Confidential Messages under Randomness Constraint," ISITA 2012, Honolulu, HI (with Yasutada Oohama).

32. "Expurgation Exponent of Leaked Information in Privacy Amplification for Binary Sources," ITW 2012, Lausanne, Switzerland.

33. "Privacy Amplification Theorem for Bounded Storage Eavesdropper," ITW 2012, Lausanne, Switzerland (with Yasutada Oohama).

34. "Broadcast Channels with Confidential Messages by Randomness Constrained Stochastic Encoder," ISIT 2012, Cambridge, MA (with Yasutada Oohama).

35. "The Rate-Distortion Function for Product of Two Sources with Side-Information at Decoders," ISIT 2011, Saint Petersburg, Russia.

Ph.D. Thesis:

    A Study of Channel Estimation and Postprocessing in Quantum Key Distribution Protocols