CIPHERTEXT MATCHING SYSTEM AND CIPHERTEXT MATCHING METHOD

摘要

A ciphertext matching system, includes: a registration target data generation apparatus, a matching request apparatus, a data matching apparatus, and a matching support apparatus. The data matching apparatus generates a first-distance-related ciphertext in which a first distance between registered data and matching target data is kept secret by random numbers. The matching support apparatus generates a public key and a secret key and transmits the generated public key to the individual apparatuses. The data matching apparatus transmits the first-distance-related ciphertext to the matching support apparatus. The matching support apparatus determines whether the first distance obtained by decrypting the first-distance-related ciphertext with the secret key is included in a set of second distances in which the registered data and the matching target data are allowable to be matched each other and transmits a result of the determination to the data matching apparatus.