| 摘要 |
PROBLEM TO BE SOLVED: To conceal index values of a database.SOLUTION: This method includes processing which groups a plurality of values of indexes included in a plurality of data blocks stored in a data storage part, specifies data for identifying a group to which the value of an index included in a data block belongs about each of the plurality of data blocks, and generates data for retrieval including the data specified about the data block and encryption data of the data block about each of the plurality of data blocks. |
