In this system for confidentially searching for similarity, data to be searched are searched for similarity to encrypted targeted data in accordance with a search request. A user terminal in this system is provided with: an input unit which receives targeted data including qualitative data and quantitative data; an encryption processing unit which encrypts the qualitative data included in the targeted data by use of an encryption method which allows the resulting encrypted qualitative data to be used to determine whether or not the original unencrypted qualitative data match other data; a similarity determination processing unit which calculates conditions such that if these conditions are satisfied by quantitative data included in the data to be searched, then the quantitative data can be determined to have a degree of similarity to the quantitative data included in the targeted data, that is equal to or greater than a certain degree of similarity; and a communication unit which transmits the encrypted quali
