Title:
ENCRYPTION SYSTEM, KEY GENERATION DEVICE, KEY GENERATION METHOD, KEY GENERATION PROGRAM, AND HOMOMORPHIC OPERATION DEVICE
Document Type and Number:
WIPO Patent Application WO/2020/174515
Kind Code:
A1
Abstract:
According to the present invention, a homomorphic public key cryptography is achieved in which encryption cannot be performed with a homomorphic operation execution authorization, by separating an encryption execution authorization and the homomorphic operation execution authorization in the homomorphic public key cryptography. The encryption system comprises: a key generation device which generates an encryption key related to an authorization to generate a ciphertext from a plaintext, a homomorphic operation key which is related to an authorization to execute a homomorphic operation of a ciphertext while being encrypted, and has weaker authorization than the encryption key, and a decryption key related to an authorization to decrypt the ciphertext; an encryption device which generates a ciphertext from a plaintext by using the encryption key; a homomorphic operation device which executes a homomorphic operation on the ciphertext by using the homomorphic operation key; and a decryption device which decrypts the ciphertext by using the decryption key.
Inventors:
FUKUDA HARUNA (JP)
TAMIYA HIROTO (JP)
ISSHIKI TOSHIYUKI (JP)
NARA MASAHIRO (JP)
TAMIYA HIROTO (JP)
ISSHIKI TOSHIYUKI (JP)
NARA MASAHIRO (JP)
Application Number:
PCT/JP2019/006969
Publication Date:
September 03, 2020
Filing Date:
February 25, 2019
Export Citation:
Assignee:
NEC CORP (JP)
International Classes:
G09C1/00
Domestic Patent References:
| WO2017126001A1 | 2017-07-27 |
Foreign References:
| JP2011107407A | 2011-06-02 | |||
| JP2016114692A | 2016-06-23 |
Attorney, Agent or Firm:
KATO, Asamichi (JP)
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