My Research

I’m a research scientist at NTT Social Informatics Laboratories in Japan. My main research area is cryptography, though I am broadly interested in information security and theoretical computer science. My research focuses on how to protect computer program while preserving its functionality, how to achieve secure computation without leaking information, and designing efficient and versatile cryptographic building blocks. More specific topics are

  • Program Obfuscation/Watermarking/Copy-Protection
  • Functional Encryption
  • Lattice-Based Cryptography
  • Quantum Cryptography

Recent activities

  • Nov. A paper on combiners for quantum cryptography on ePrint archive.
  • Nov. 2023. The result on qunatum public key encryption was accepted as a contributed talk of QIP 2024.
  • Aug. A paper on unclonable encryption was accepted by TCC 2023.
  • Aug. A paper on publicly verifiable deletion was accepted by TCC 2023.
  • Aug. Invited to be a program committee member of CRYPTO 2024.
  • Jul. Invited to be a program committee member of Eurocrypt 2024.
  • Jul. 2023. The full version of tight SPS paper was accepted by Journal of Cryptology.
  • Jun. 2023. The result on obufscation for quantum circuits was accepted as a contributed talk of QCrypt 2023.

Contact Information

  • Please send official invitation mails (PC members, invited talks, etc.) to
    firstname dot lastname at ntt dot com (firstname = ryo)
  • For other mails (review requests etc.) :
    1. firstname at lastname dot info
    2. firstname dot lastname at gmail dot com
  • Address: NTT Corporation
    3-9-11 Midoricho, Musashino-shi, Tokyo 180-8585 Japan

Short Bio.

On pronunciation of my first name

I do not know English words whose pronunciation are exactly the same as that of Ryo. The pronunciation of Rio, which is the name of a city in Brazil, is similar to that of Ryo.