Security Technologies without User Interaction in Distributed Environment

2023 Fiscal Year Final Research Report

• Project/Area Number: 18K11304
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 60070:Information security-related
• Research Institution: Hosei University
• Principal Investigator: Obana Satoshi 法政大学, 情報科学部, 教授 (70633600)
• Project Period (FY): 2018-04-01 – 2024-03-31
• Keywords: マルチパーティ計算 / 非対話型プロトコル / 通信量削減

Outline of Final Research Achievements

We have developed cryptographic protocols in a distributed environment. The notable feature of proposed protocols is that no interaction among users is required. More concretely, we have developed cryptographic protocols such as NIMPC (Non-Interactive Multi Party Computation), CDSS (Cheating Detectable Secret Sharing), and information theoretically secure authenticated encryption secure against replay attack. Here, NIMPC is a cryptographic primitive which enables users to evaluate any function with input secret information of users without revealing their secret information. Cheating Detectable Secret Sharing is a variant of secret sharing (a cryptographic protocol for split secret information into pieces (called share) in such a way that no partial information about the secret is revealed unless certain number of pieces are obtained by the adversary) with an extra functionality to detect the presence of forged shares in reconstructing the secret.

Free Research Field

暗号・情報セキュリティ

Academic Significance and Societal Importance of the Research Achievements

分散型の暗号プロトコルでは，複雑な通信がプロトコルのデッドロックの要因となったり，プロトコルの実行速度のボトルネックとなることが多く，ユーザ間での複雑な通信を可能な限り排除することが理想である．本研究で提案した暗号プロトコルは全て，非常に単純な一方向の通信で構成されており，通信に起因するデッドロックの発生やパフォーマンス低下を防ぐことが可能となっている．しかし，複雑な通信を行うプロトコルと比較して，非対話的なプロトコルは通信量の増大を招くことが多いが，本研究ではNIMPC(非対話型のマルチパーティ計算)において，通信量の削減に成功している点で学術的意義は大きいと言える．