A data certification system includes a proof information generation unit that generates certification information for certifying non-falsification of raw data, and generates proof information including the certification information and time information representing the time of the generation of the certification information. A server transmission unit transmits the proof information which is received by a client reception unit. A time information acquisition unit acquires the time information representing the time of the generation of the certification information from the proof information. A report generation unit generates report data in which the time information and publishing destination information representing a publishing destination are included in the raw data. A transfer unit transfers the raw data, the proof information, and the report data to a publishing server which releases the report data. An output unit outputs the report data.