Patent ID: 9418238
Filing Date: 2016-08-16
CPC Classification: G06F,H04L

Claim Text:
1. A search system comprising an information processing device, a search device, and a corresponding keyword management device, the information processing device including: a corresponding keyword storage unit having a processor that stores corresponding keyword data generated by the corresponding keyword management device as data associating a search keyword with a corresponding keyword group including one or more corresponding keywords; a search keyword input unit having a processor that inputs a search keyword; a corresponding keyword group acquisition unit having a processor that obtains from the corresponding keyword data stored in the corresponding keyword storage unit a corresponding keyword group associated with the search keyword input by the processor of the search keyword input unit; an encrypted keyword group generation unit having a processor that encrypts corresponding keywords included in the corresponding keyword group obtained by the processor of the corresponding keyword group acquisition unit, generating an encrypted keyword group; a search request data transmission unit having a processor that transmits to the search device via a network search request data including the encrypted keyword group generated by the processor of the encrypted keyword group generation unit; a search response data receiving unit having a processor that receives via the network search response data transmitted from the search device; and a search result output unit having a processor that decrypts encrypted data included in the search response data received by the processor of the search response data receiving unit, and outputs as a search result search data obtained by decryption; the search device including: an encrypted data storage unit having a processor that stores encrypted data generated by encrypting each search data and an encrypted keyword generated by encrypting a corresponding keyword, the encrypted data and the encrypted keyword being associated with each other; a search request data receiving unit having a processor that receives via the network the search request data transmitted by the information processing device; an encrypted data search unit having a processor that obtains encrypted data associated with a search key from the encrypted data storage unit using as the search key an encrypted keyword included in the encrypted keyword group in the search request data, based on the search request data received by the processor of the search request data receiving unit; and a search response data transmission unit having a processor that transmits via the network the search response data including the encrypted data obtained by the processor of the encrypted data search unit; the corresponding keyword management device including: an appearance frequency storage unit having a processor that stores appearance frequency data defining a search keyword and an appearance frequency of the search keyword, the appearance frequency indicating a rate of search data associated with the search keyword; a corresponding keyword number calculation unit having a processor that calculates as a corresponding keyword number a number of corresponding keywords to be associated with the search keyword, according to the appearance frequency of the search keyword defined in the appearance frequency data stored in the appearance frequency storage unit; a corresponding keyword group generation unit having a processor that generates as a corresponding keyword group a same number of corresponding keywords as the corresponding keyword number calculated by the processor of the corresponding keyword number calculation unit; and a corresponding keyword data generation unit having a processor that generates the corresponding keyword data by associating the search keyword defined in the appearance frequency data with the corresponding keyword group generated by the processor of the corresponding keyword group generation unit, wherein the processor of the corresponding keyword number calculation unit of the corresponding keyword management device calculates as a corresponding keyword selection rate a rate of selecting each corresponding keyword from the corresponding keyword group of the search keyword, based on the appearance frequency of the search keyword defined in the appearance frequency data, wherein the processor of the corresponding keyword data generation unit of the corresponding keyword management device generates, as corresponding keyword selection rate data, data associating the search keyword with the corresponding keyword group and each corresponding keyword selection rate, the search system further comprising: an encrypted data generation device including: a search data storage unit having a processor that stores search data and a search keyword by associating the search data and the search keyword with each other; a corresponding keyword selection rate storage unit having a processor that stores the corresponding keyword selection rate data generated by the processor of the corresponding keyword management device; a corresponding keyword selection unit having a processor that obtains from the corresponding keyword selection rate data the corresponding keyword group associated with the search keyword stored in the search data storage unit, and selects at least any one of corresponding keywords included in the corresponding keyword group obtained, according to the corresponding keyword selection rate included in the corresponding keyword selection rate data; and an encrypted data generation unit having a processor that generates encrypted data by encrypting the search data stored in the search data storage unit, and generates an encrypted keyword by encrypting the corresponding keyword selected by the processor of the corresponding keyword selection unit, wherein the encrypted data storage unit of the search device stores the encrypted data and the encrypted keyword generated by the processor of the encrypted data generation device by associating the encrypted data and the encrypted keyword with each other.