E-commerce system and its authentication method

An authentication method of an e-commerce system comprising:

• a procedure request receiving step of receiving, by a procedure request receiving unit, a procedure request for performing an ordering procedure of an item from a user device;
• a first screen sending step of sending, by a first screen sending unit, to the user device, an authentication screen for obtaining authentication information of a user of the user device in a case where the user of the user device is not authenticated based on communication control information that is stored in the user device and included in the procedure request, or a review screen for displaying a delivery address of the item in a case where the user is authenticated based on the communication control information;
• a second screen sending step of obtaining, by a second screen sending unit, the authentication information that is input in the authentication screen, causing the user device to store the communication control information in accordance with the obtained authentication information, and sending the review screen to the user device;
• a delivery address change request receiving step of receiving, by a delivery address change request receiving unit, a request for changing the delivery address sent from the user device in response to an operation on the review screen;
• and
• a re-authentication step of performing, by a re-authentication unit, re-authentication of the user in a case where the request for changing the delivery address is received and the first screen sending unit has sent the review screen to the user device, and authentication of the user based on the communication control information without performing re-authentication of the user in a case where the request for changing the delivery address is received and the first screen sending unit has sent the authentication screen to the user device.

A non-transitory computer readable information storage medium that stores a program for causing a computer to function as:

• a procedure request receiving unit configured to receive a request for performing an ordering procedure of an item from a user device;
• a first screen sending unit configured to send, to the user device, an authentication screen for obtaining authentication information of a user of the user device in a case where the user of the user device is not authenticated based on communication control information that is stored in the user device and included in the procedure request, or a review screen for displaying a delivery address of the item in a case where the user is authenticated based on the communication control information;
• a second screen sending unit configured to obtain the authentication information that is input in the authentication screen, causing the user device to store the communication control information in accordance with the obtained authentication information, and send the review screen to the user device;
• a delivery address change request receiving unit configured to receive a request for changing the delivery address sent from the user device in response to an operation on the review screen;
• and
• a re-authentication unit configured to perform re-authentication of the user in a case where the request for changing the delivery address is received and the first screen sending unit has sent the review screen to the user device, and not to perform re-authentication of the user but to perform authentication of the user based on the communication control information in a case where the request for changing the delivery address is received and the first screen sending unit has sent the authentication screen to the user device.