Patent ID: 8024307

Claim:
An information processing apparatus comprising: a control unit configured to display a plurality of folders and a plurality of files on a display device; a designation unit configured to designate a folder from the plurality of displayed folders based on a user's selection; a first generation unit configured to generate hash data for the folder designated by the designation unit, hash data for each of folders which are derived from the folder designated by the designation unit, hash data for each of files included in the folder designated by the designation unit, and hash data for each of files included in each of folders which are derived from the folder designated by the designation unit; a second generation unit configured to generate one multiplexed hash data with a fixed length by repeating a multiplexing process for the hash data generated for each of the folders and each of the files, from a folder of a lowermost layer to the designated folder in turn, wherein the folder of the lowermost layer is derived from the designated folder; and a storage medium configured to store the one multiplexed hash data with a fixed length generated by the second generation unit in association with the folder designated by the designation unit, wherein if a folder includes a plurality of files, then the second generation unit repeats the multiplexing process for the hash data for each of the plurality of files according to update time orders of the plurality of files included in the folder.