Research on Advanced Cryptography with Updatability for Devices with Low Computational Resources

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K18049
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 60070:Information security-related
• Research Institution: Osaka University
• Principal Investigator: Yanai Naoto 大阪大学, 情報科学研究科, 助教 (30737896)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 高機能暗号 / ネットワーク / 暗号化状態検索 / コンピュータセキュリティ

Outline of Final Research Achievements

For aggregate signatures, which are an advanced cryptographic primitive to aggregate individual signatures, a security proof with a tight reduction was presented, and then a prototype implementation on a software router was provided as an application to networks. Hence, from theory to implementation, advanced cryptography had been discussed through a class of aggregate signatures. Meanwhile, searchable encryption that allows a user to search encrypted data was discussed. In particular, a key-aggregate searchable encryption scheme that can provide user-level access control for each file in the multi-user setting was proposed. The proposed scheme is the first scheme whose security can be proven in the multi-user setting. The scheme was also implemented, and source code is publicly available from GitHub.

Free Research Field

情報セキュリティ

Academic Significance and Societal Importance of the Research Achievements

応用が不透明である高機能暗号について、理論から応用技術まで一貫して検討を行ったことに重要な学術的意義と社会的意義がある。理論研究の面からは社会的課題を踏まえた暗号理論を示しており、また、応用研究からは従来技術ではなしえなかった性能や仕様を達成するに至っている。とくに実装面に至る成果はプログラムを公開することで、再現性も確保している。