Similarity calculation system, similarity calculation apparatus, similarity calculation method, and similarity calculation program

Abstract

A similarity calculation system calculating a distance between a first vector stored in a similarity calculation apparatus and a second vector entered from an input terminal wherein the similarity calculation apparatus transmits to the input terminal a ciphertext of each element of the first vector and a weighted distance table with respect to combinations of possible values of the elements of the first vector and the second vector, and the input terminal refers to the weighted distance table to calculate a ciphertext of element distances for all combinations of the value of a single element of the second vector and possible values of elements of the first vector, calculates the ciphertexts of the sum of the element distances for each element of the second vector using additive homomorphic encryption, and transmits the ciphertext of the sum to the similarity calculation apparatus.

CPC Classifications