ENCRYPTED DATABASE SYSTEM, CLIENT TERMINAL, DATABASE SERVER, DATA LINKING METHOD, AND PROGRAM

摘要

Provided is an encrypted database system and the like that links a plurality of tables without decryption, reducing the risk of data associativity being leaked. A client terminal (10) decrypts a first table having an input a-th column and b-th column of data and a second table having a c-th column of data by means of a pre-recorded secret key, outputs the result to an encrypted database server (50), and transmits to the encrypted database server (50) a search key generated from the secret key along with a partial link command resulting from linking the encrypted first table and second table with the key being the b-th column and c-th column with respect to data for which the value of the a-th column is q. The encrypted database server (50) receives and records the encrypted first and second tables, extracts the data for which the a-th column of values is q from the first and second tables encrypted using the search key, links to the extracted data with the b-th column and c-th column as keys, and returns the result.