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1. (WO2018100740) CIPHER TEXT VERIFICATION SYSTEM AND CIPHER TEXT VERIFICATION METHOD

Pub. No.:    WO/2018/100740    International Application No.:    PCT/JP2016/085951
Publication Date: Fri Jun 08 01:59:59 CEST 2018 International Filing Date: Sat Dec 03 00:59:59 CET 2016
IPC: H04L 9/32
G06F 21/60
Applicants: NEC CORPORATION
日本電気株式会社
Inventors: ISSHIKI, Toshiyuki
一色 寿幸
HIGO, Haruna
肥後 春菜
Title: CIPHER TEXT VERIFICATION SYSTEM AND CIPHER TEXT VERIFICATION METHOD
Abstract:
Provided is a cipher text verification system which can guarantee no occurrence of leakage of information about the distance between data, and in which the most part of a verification process does not depend on a parameter having an allowable ambiguity. The cipher text verification system includes a registration data creating device, a verification requesting device, a data verifying device, and a verification assistant device. The data verifying device creates a cipher text which is related to a first distance between registration data and data to be verified and in which the first distance is concealed by a random number. The verification assistant device creates a public key and a secret key, and transmits the created public key to each of the devices. The data verifying device transmits, to the verification assistant device, the cipher text related to the first distance. The verification assistant device determines whether or not the first distance obtained by decoding, with the secret key, the cipher text related to the first distance is included in a set of second distances which are allowable on the assumption that the registration data matches with the data to be verified, and transmits the determination result to the data verifying device.