Title:
CONVERSION KEY GENERATION DEVICE, CIPHERTEXT CONVERSION DEVICE, SECRET INFORMATION PROCESSING SYSTEM, CONVERSION KEY GENERATION METHOD, CONVERSION KEY GENERATION PROGRAM, CIPHERTEXT CONVERSION METHOD, AND CIPHERTEXT CONVERSION PROGRAM
Document Type and Number:
WIPO Patent Application WO/2019/130528
Kind Code:
A1
Abstract:
In the present invention, a key acquisition part (411) acquires, from among multiple pairs of decryption keys and public keys, a decryption key ski from the conversion-source pair and a public key pkj from the conversion-destination pair. A conversion key generation part (412) encrypts, by using the public key pkj, the decryption key ski acquired by the key acquisition part (411) and generates a conversion key rki
→j for converting a ciphertext encrypted using a public key pki from the conversion-source pair into a converted ciphertext which can be decrypted using a decryption key skj from the conversion-destination pair. An output part (413) outputs the conversion key rki
→j generated by the conversion key generation part (412).
Inventors:
YASUDA SATOSHI (JP)
KOSEKI YOSHIHIRO (JP)
KAWAI YUTAKA (JP)
HIROMASA RYO (JP)
KOSEKI YOSHIHIRO (JP)
KAWAI YUTAKA (JP)
HIROMASA RYO (JP)
Application Number:
PCT/JP2017/047148
Publication Date:
July 04, 2019
Filing Date:
December 28, 2017
Export Citation:
Assignee:
MITSUBISHI ELECTRIC CORP (JP)
International Classes:
H04L9/14; G09C1/00
Domestic Patent References:
| WO2014010202A1 | 2014-01-16 | |||
| WO2016112954A1 | 2016-07-21 |
Foreign References:
| JP2015019333A | 2015-01-29 | |||
| JP2017225116A | 2017-12-21 |
Other References:
LOPEZ-ALT, A. ET AL.: "On-the-fly multiparty computation on the cloud via multikey fully homomorphic encryption", CRYPTOLOGY EPRINT ARCHIVE, 20 February 2013 (2013-02-20), pages 1 - 44, XP061007327, Retrieved from the Internet [retrieved on 20180320], doi:10.1145/2213977.2214086
Attorney, Agent or Firm:
MIZOI INTERNATIONAL PATENT FIRM (JP)
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