Keitaro Hashimoto (𣘺本 啓太郎)

Researcher at AIST | Researching cryptography to realize a secure world!

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I am a researcher at Security Assurance Scheme Research Team in Cyber Physical Security Research Center, National Institute of Advanced Industrial Science and Technology (AIST). I received my Bachelor’s degree in Engineering, Master’s degree in Engineering and Ph.D. in Engineering from Tokyo Institute of Technology in 2018, 2020 and 2023, respectively. My adviser is Prof. Wakaha Ogata. Furthermore, I completed Progressive Graduate Minor in Cybersecurity in 2020. Before I become a resercher at AIST, I worked as a research assistant at AIST from June 2020 to March 2023, and as a research fellowship for young scientists from April 2022 to March 2023.

I am skilled at provable security in cryptography. My research interests are board range of cryptography and information security, especially real-world cryptraphic technologies such as secure messaging and how to propote social implementation of such technologies. Also, I love to systematically analyze security of cryptographic primitives/protocols.

I am a compassionate and cooperative professional. I received the Outstanding Student Award in 2020, Tsujii Shigeo Security Award in 2021, 2022 and 2023, and Seiichi Tejima Ph.D. dissertation award in 2024.

News

Oct 01, 2024 Our new paper titled “A Generic Construction of Deletable Registered Attribute-Based Encryption from Slotted Registered Attribute-Based Encryption” will be presented in a domestic conference CSS 2024.
Jul 02, 2024 Our new paper titled “Security Model for Authenticated Key Exchange, Reconsidered” has been accepted at SCN 2024.
Jul 01, 2024 Our new paper titled “Towards a Tightly Secure Signature in Multi-User Setting with Corruptions Based on Search Assumptions” has been accepted at CFAIL 2024.

Selected publications

  1. CCS:HKP22
    How to Hide MetaData in MLS-Like Secure Group Messaging: Simple, Modular, and Post-Quantum
    Keitaro Hashimoto, Shuichi Katsumata, and Thomas Prest
    In The ACM Conference on Computer and Communications Security (ACM CCS), November 2022
  2. J. Cryptol.:HKKP22
    An Efficient and Generic Construction for Signal’s Handshake (X3DH): Post-Quantum, State Leakage Secure, and Deniable
    Keitaro Hashimoto, Shuichi Katsumata, Kris Kwiatkowski, and Thomas Prest
    Journal of Cryptology, May 2022
    Full version of [PKC:HKKP21].
  3. CCS:HKPPW21
    A Concrete Treatment of Efficient Continuous Group Key Agreement via Multi-Recipient PKEs
    Keitaro Hashimoto, Shuichi Katsumata, Eamonn W. Postlethwaite, Thomas Prest, and Bas Westerbaan
    In The ACM Conference on Computer and Communications Security (ACM CCS), November 2021