Receipt server, electronic receipt system, and program

A receipt server connected over a network to a point-of-sale (POS) terminal, the receipt server comprising:

• a network interface,
• a storage unit, and
• a processor configured to control the network interface and the storage unit to:
• store electronic receipt data received from the POS terminal,
• determine whether the electronic receipt data indicates that a digital authentication service should be applied thereto,
• when the electronic receipt data indicates that the digital authentication service should be applied thereto, request and receive a time stamp token (TST) from a time stamping authority server, wherein the TST is generated based on a hash of the electronic receipt data and a time of generation,
• when the TST is received, store the TST in association with the electronic receipt data, and
• in response to a request for certified electronic receipt data, transmit the electronic receipt data with the associated TST.

A non-transitory computer readable medium containing a program causing a server to perform an electronic receipt management method comprising the steps of:

• storing electronic receipt data received from a point-of-sale terminal connected to the server over a network;
• determining whether the electronic receipt data indicates that a digital authentication service should be applied thereto;
• when the electronic receipt data indicates that the digital authentication service should be applied thereto, requesting and receiving a time stamp token (TST) from a time stamping authority server, wherein the TST is generated based on a hash of the electronic receipt data and a time of generation;
• storing the TST in association with the electronic receipt data;
• and
• in response to a request for certified electronic receipt data, transmitting the electronic receipt data with the associated TST.