ENCRYPTED TEXT MATCHING SYSTEM, METHOD, AND COMPUTER READABLE MEDIUM

摘要

An encrypted text matching system includes: an auxiliary data generating unit configured to generate first auxiliary data and second auxiliary data, respectively, which are for verification of matching between a first encrypted text that is obtained by encrypting input data and is registered with a storage device and a second encrypted text that is obtained by encrypting input data to be matched, the verification being performed by using a Hamming distance between plaintexts; and matching determining unit configured to perform one-way conversion on at least part of the first auxiliary data, perform one-way conversion on intermediate data that is generated based on a difference between the first encrypted text and the second encrypted text and on the second auxiliary data, and determine, by using a result of the one-way conversion performed on the intermediate data as well as using the first auxiliary data that underwent the one-way conversion, whether a Hamming distance between plaintexts is equal to or less than a predetermined certain value, the Hamming distance corresponding to the difference between the first encrypted text and the second encrypted text.

主权项

1. An encrypted text matching system comprising:
an auxiliary data generating unit configured to generate first auxiliary data and second auxiliary data, respectively, which are for verification of matching between a first encrypted text that is obtained by encrypting input data and is registered with a storage device and a second encrypted text that is obtained by encrypting input data to be matched, the verification being performed by using a Hamming distance between plaintexts; and a matching determining unit configured to perform one-way conversion on at least part of the first auxiliary data, perform one-way conversion on intermediate data that is generated based on a difference between the first encrypted text and the second encrypted text and on the second auxiliary data, and determine, by using a result of the one-way conversion performed on the intermediate data as well as using the first auxiliary data that underwent the one-way conversion, whether a Hamming distance between plaintexts is equal to or less than a predetermined certain value, the Hamming distance corresponding to the difference between the first encrypted text and the second encrypted text.