Patent ID: 7631185

Claim:
A file editing system, comprising: a file management server device for managing files, each file containing a plurality of block data and block identification information for each block data, and the block data being enciphered in units of blocks; and at least one client device, which makes an access to the file management server device to obtain the block data corresponding to a desired version of a desired file managed by the file management server device, the client device including; deciphering means for deciphering the block data obtained from the file management server device, in units of blocks by using a prescribed decipher key; editing means for editing the desired version of the desired file formed by the block data deciphered by the deciphering means; editing procedure generation means for generating editing procedure data indicating a procedure to obtain an editing made in the desired version of the desired file by the editing means; editing procedure conversion means for converting the editing procedure data for the desired version of the desired file generated by the editing procedure generation means into editing procedure data for a latest version of the desired file; record management information generation means for generating record management information indicating a result of the editing made by the editing means, according to the editing procedure data for the latest version of the desired file obtained by the editing procedure conversion means; enciphering means for enciphering the record management information generated by the record management information generation means, in units of blocks by using a prescribed cipher key, to obtain enciphered record management information; and communication means for transmitting the enciphered record management information obtained by the enciphering means to the file management server device; wherein the file management server device includes: record management means for carrying out a record management of the desired file according to the enciphered record management information received from the client device and the block identification information for each block data.