Patent ID: 7228416
Filing Date: 2007-06-05
Classification: H04L

Abstract:
1. A data relay server for accessing a database server via a communication network in accordance with a query for a database received from a client computer, comprising: first means for encrypting retrieval condition data included in a query received from the client computer; second means for producing a query message destined for said database server, including the retrieval condition data encrypted by said first means and an identifier of an encryption function used to generate the encrypted retrieval condition data; third means for transmitting the query message produced by said second means to said communication network; fourth means for receiving from said database server via said communication network, as a retrieval result, data matched with the encrypted retrieval condition data retrieved by matching the data with the encrypted retrieval condition data, wherein the matching is performed by encrypting at least one data item read out from a database in said database server using the encryption function designated by the identifier in the query message and comparing the encrypted at least one data item to the encrypted retrieval condition data; and fifth means for producing a response message for the client computer based on the retrieval result received by said fourth means and transferring the response message to the client computer.