My Research


I’m a research scientist at NTT 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
  • Functional Encryption
  • Structure Preserving Signature
  • Lattice-Based Cryptography

Recent activities


Contact Information


  • E-mail: firstname dot lastname at gmail dot com
  • Address: NTT Secure Platform Laboratories
    3-9-11 Midoricho, Musashino-shi, Tokyo 180-8585 Japan

Short Bio.


On pronunciation of my first name


I found that it is not easy for people who do not speak Japanese to pronounce ``Ryo”. 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.