A time certification server includes a receiving section that receives an issue request for a time certification code and terminal information; a temporal change information input section that inputs temporal change information; a first code generating section that generates a first code based on the temporal change information and outputs the first code; a second code generating section that generates a second code based on the terminal information and the first code and outputs the second code; a transmitting section that transmits the second code to the terminal apparatus as a time certification code; a time certification code memory section that stores the time certification code in correlation with time; and a certification processing section that searches the time certification code memory section by using the time certification code received, thereby obtaining time, and outputs certification information based on the time obtained to the terminal apparatus.