Patent ID: 7529973

Claim:
An alteration checking apparatus comprising: a back-up unit that copies original data from an original data storage unit to a back-up data storage unit as back-up data without checking alteration of the original data; a list storing unit that stores information relating to the original data copied by the back-up unit, the information indicating that authenticity is assured to the original data copied by the back-up unit; and an alteration checking unit that, after copying of the original data as the back-up data is over, decides whether the original data has been altered based on the information relating to the original data copied and original data stored in the original data storage unit and notifies a user of decided alteration, and wherein the alteration checking unit writes information in the list storing unit relating to original data that have been copied successfully as the back-up data and relating to original data that are decided to be not altered, the information indicating that authenticity of the original data is assured.