The present invention provides a technique that allows for a valid modification that is authorized by the author of data, while assuring the originality of the data. An information processing apparatus for processing original data created by a predetermined author is provided. The information processing apparatus includes a modification-information storing unit for storing modification information regarding a modification onto a storage medium when the original data is modified, and a modification-assuring-information creating unit for creating modification assuring information for assuring that the modification information is true.