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

• Apr. 2023. A paper on publicly verifiable deletion on arXiv and ePrint archive.
• Apr. 2023. Invited to be a program committee member of Asiacrypt 2023.
• Apr. 2023. A paper on quantum public key encryption on ePrint archive and arXiv.
• Feb. 2023. A paper on public key encryption with secure key leasing on ePrint archive and arXiv.
• Feb. 2023. A paper on obfuscation for quantum circuits on ePrint archive.
• Feb. 2023. A paper on certified everlasting functional encryption on ePrint archive and arXiv.
• Feb.2023. A paper on unclonable cryptography on ePrint archive and arXiv.
• Feb. 2023. A paper on obfuscation for quantum circuits accepted by STOC 2023.
• Feb. 2023. A paper on public key encryption with secure key leasing was accepted by Eurocrypt 2023.
• Dec. 2022. Invited to be a program committee member of ACM CCS 2023.

Contact Information

• Please send official invitation mails (PC members, talks, etc.) to
  firstname dot lastname dot zk at hco dot ntt dot co dot jp (firstname = ryo)
• For other mails:
  
  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.

• Visiting associate professor at School of Computing at Tokyo Institute of Technology from 07/2016 -
• Visiting researcher at Northeastern University at Boston during Oct. 2014 - Dec. 2015 (hosted by Daniel Wichs)
• Obtained my Dr. Sci. (corresponding to Ph.D.) from Tokyo Institute of Technology in September 2010 (adviser: Keisuke Tanaka)
• Joined NTT Information Sharing Platform Laboratories (now, NTT Social Informatics Laboratories) in 2007
• Completed my Master’s degree in Informatics at Graduate School of Informatics Kyoto University in 2007
• Completed my Bachelor’s degree in Engineering at Kyoto University in 2005

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.