SERVER DEVICE, INFORMATION PROVIDING SYSTEM, INFORMATION PROVIDING METHOD, INFORMATION PROVIDING PROGRAM, AND COMPUTER-READABLE RECORDING MEDIUM FOR RECORDING THE INFORMATION PROVIDING PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a server device and an information providing system that can stepwise disclose data for clients even when transmitting related data altogether to the clients. SOLUTION: The server device is provided with a first encryption section (S701) that encrypts sub data in pairs with main data by using a first encryption key to produce first encryption data; a second encryption section (S702) that combines the main data and the first encryption data and encrypts the combined data by using a second encryption key to produce second encryption data; a first transmission section (S704) that transmits the second encryption data to a client device in response to the reception of a first request from the client device; a second transmission section (S706) that transmits a second decoding key corresponding to the second encryption key in response to the reception of a second request from the client device to which the second encryption data are transmitted; and a third transmission section (S708) that transmits a first decoding key corresponding to the first encryption key in response to the reception of a third request from the client device to which the second decoding key is transmitted.