A cryptographic scheme maintaining security for cloud environments

• Project/Area Number: 24700009
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Fundamental theory of informatics
• Research Institution: National Institute of Information and Communications Technology
• Principal Investigator: Emura Keita 国立研究開発法人情報通信研究機構, ネットワークセキュリティ研究所セキュリティ基盤研究室, 主任研究員 (30597018)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2015: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2014: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2013: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2012: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
• Keywords: 鍵付き準同型暗号 / 適応的暗号文選択攻撃 / 準同型暗号 / 公開鍵暗号 / 国際会議採録 / 安全性証明の修正

Outline of Final Research Achievements

It is widely recognized that homomorphic encryption never achieves security against adaptive chosen-ciphertext attack (CCA security). We propose a homomorphic encryption scheme with CCA security by adequately modifying the model of homomorphic encryption which we call keyed-homomorphic encryption. Our result was accepted to PKC 2013 which is a well-known international workshop in the public key encryption area, and was awarded the SCIS Innovation Paper Award from IEICE in 2012.

Research Products

• [Journal Article] Chosen Ciphertext Secure Keyed-Homomorphic Public-Key Encryption (2013)
  • Author(s): Keita Emura, Goichiro Hanaoka, Koji Nuida, Go Ohtake, Takahiro Matsuda, Shota Yamada
  • Journal Title: IACR Cryptology ePrint Archive Volume: 2013 Pages: 390-390
• [Presentation] 鍵付き準同型IDベース暗号 (2015)
  • Author(s): 江村 恵太, 花岡 悟一郎, 松田 隆弘, 縫田 光司, 山田 翔太
  • Organizer: 暗号と情報セキュリティシンポジウム (SCIS) 2015
  • Place of Presentation: 福岡県北九州市小倉リーガロイヤルホテル小倉
  • Year and Date: 2015-01-20 – 2015-01-23
• [Presentation] Chosen Ciphertext Secure Keyed-Homomorphic Public-Key Encryption (2013)
  • Author(s): Keita Emura, Goichiro Hanaoka, Go Ohtake, Takahiro Matsuda, Shota Yamada
  • Organizer: Public Key Cryptography 2013
  • Place of Presentation: Nara Prefectural New Public Hall, Nara, Japan
• [Remarks] NICT研究成果公開システム: 鍵付き準同型IDベース暗号
  • URL: http://seika-kokai.nict.go.jp/jp/whatnew/WhatNewDetail.do?inputData.data_sei_id=201403116
• [Remarks] (タイトルは以下)
  • URL: http://seika-kokai.nict.go.jp/jp/whatnew/WhatNewDetail.do?inputData.data_sei_id=201201390