File editing system and shared file editing system with file content secrecy, file version management, and asynchronous editing

• US 6,760,840 B1
• Filed: 08/26/1998
• Issued: 07/06/2004
• Est. Priority Date: 03/15/1994
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Murato, Masao, Shimbo, Atsushi, Takahashi, Toshinari, Tomoda, Ichiro
• Primary Examiner(s): Laufer, Pinchus M.
• Application Number:
  US09/140,671
• Time in Patent Office: 2,141 Days
• Field of Search: 380/3, 380/4, 380/9, 380/29, 380/32, 380/37, 380/49, 707/201, 707/203, 707/500, 707/511, 707/530, 707/539
• US Class Current: 713/165
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 21/6227 where protection concerns the structure of data, e.g. records, types, queries
• CPC Class Codes: G06F 2221/2147 Locking files
• CPC Class Codes: G06F 40/166 Editing, e.g. inserting or deleting
• CPC Class Codes: G06Q 10/10 Office automation; Time management

Abstract

A file editing system that provides a high file content secrecy, a file version management, and an asynchronous editing is disclosed. For a high file content secrecy, the block data of files managed by a file management server device are enciphered in units of blocks, and a client device obtains the block data of the desired file in enciphered state, deciphers the obtained block data in units of blocks, carries out an editing of the desired file to obtain editing data, enciphers the editing data in units of blocks, and transmits the enciphered editing data to the file management server device. For asynchronous editing, the system includes a unit for generating editing procedure data that indicates a procedure to obtain the editing made in the desired version of the desired file by each client device, a unit for converting the editing procedure data for the desired version of the desired file into converted editing procedure data for the latest version of the desired file, and a unit for generating record management information indicating a result of the editing made by each client device according to the converted editing procedure data for the latest version of the desired file.

Claims

1. 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, the block data being enciphered in units of blocks, and the file management server device managing the files according to the block identification information for each block data; and

at least one client device, which makes an access to the file management server device to obtain the block data belonging to 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 file formed by the block data deciphered by the deciphering means, to obtain editing data indicating an editing made in the desired file;

enciphering means for enciphering the editing data obtained by the editing means, in units of blocks by using a prescribed cipher key, to obtain enciphered editing data; and

communication means for transmitting the enciphered editing data obtained by the enciphering means to the file management server device, such that the file management server device manages the desired file according to the enciphered editing data received from the client device.

2. The system of claim 1, wherein the client device obtains the block data corresponding to a desired version of the desired file from the file management server device, and the file management server device has record management means for carrying out a record management of the desired file according to the enciphered editing data for the desired version of the desired file received from the client device.

3. The system of claim 1, wherein the client device obtains the block data corresponding to a desired version of the desired file from the file management server device, and the file management server device has record management means for carrying out a record management of the desired file according to the enciphered editing data for a latest version of the desired file received from the client device.

4. The system of claim 1, wherein the file management server device has request accepting means for accepting access requests with respect to an identical file from more than one client devices asynchronously, such that said more than one client devices carry out asynchronous editing with respect to said identical file.

5. The system of claim 1, wherein the file management server device has file managing means for managing each block data in a state of being enciphered by a stream cipher scheme, and the enciphering means enciphers the editing data by the stream cipher scheme.

6. The system of claim 1, wherein the client device further includes:

access request means for issuing an access request in terms of system calls provided by an operating system, with respect to a file formed by the block data which are enciphered and managed by the file management server device;

system call table means for registering address pointers corresponding to the system calls; and

file access processing means for obtaining a file access request to be transmitted from the client device to the file management server device, according to the address pointers registered in the system call table means corresponding to the system calls specified by the access request issued at the access request means.

7. A method of file editing in a file editing system formed by a file management server device and at least one client device, comprising the steps of:

managing files at the file management server device, each file containing a plurality of block data and block identification information for each block data, the block data being enciphered in units of blocks, and the file management server device managing the files according to the block identification information for each block data;

making an access to the file management server device to obtain the block data belonging to a desired file managed by the file management server device, at the client device;

deciphering the block data obtained from the file management server device, in units of blocks by using a prescribed decipher key, at the client device;

editing the desired file formed by the block data deciphered by the deciphering step to obtain editing data indicating an editing made in the desired file, at the client device;

enciphering the editing data obtained by the editing step, in units of blocks by using a prescribed cipher key, to obtain enciphered editing data at the client device; and

transmitting the enciphered editing data obtained by the enciphering step from the client device to the file management server device, such that the file management server device manages the desired file according to the enciphered editing data received from the client device.

8. A client device for making an access to a file management server device, the client device comprising:

a receiving unit that receives block data belonging to a desired file from the file management server device, where the desired file contains a plurality of block data and block identification information for each block data, and the block data is enciphered in units of blocks;

a deciphering unit that deciphers the block data received by the receiving unit, in units of blocks by using a prescribed decipher key;

an editing unit that edits the desired tile formed by the block data deciphered by the deciphering unit, to obtain editing data indicating an editing made in the desired file;

an enciphering unit that enciphers the editing data obtained by the editing unit, in units of blocks by using a prescribed cipher key, to obtain enciphered editing data; and

a communication unit that transmits the enciphered editing data obtained by the enciphering unit to the file management server device, such that the file management server device, manages the desired file according to the enciphered editing data received from the client device and the block identification information for each block data.

9. A method for making an access from a client device to a file management server device, the method comprising the steps of:

receiving block data belonging to a desired file from the file management server divice, where the desired file contains a plurality of block data and block identification information for each block data, and the block data is enciphered in units of block;

deciphering the block data received by the receiving step, in units of blocks by using a prescribed decipher key;

editing the desired file formed by the block data deciphered by the deciphering step to obtain editing data indicating an editing made in the desired file;

enciphering the editing data obtained by the editing step, in units of blocks by using prescribed cipher key, to obtain enciphered editing data; and

transmitting the enciphered editing data obtained by the enciphering step to the file management server device, such that the file management server device manages the desired file according to the enciphered editing data received from the client device and the block identification information for each block data.

10. An article of manufacture, comprising:

a computer usable medium having computer readable program code means embodied therein for causing a computer to function as a client device for making an access to a file management server device, the computer readable program code means including;

first computer readable program code means for causing said computer to receive block data belonging to a desired file from the file management server device, where the desired file contains a plurality of block data and block identification information for each block data, and the block data is enciphered in units of blocks;

second computer readable program code means for causing said computer to decipher the block data received by the first computer readable program code means, in units of blocks by using a prescribed decipher key;

third computer readable program code means for causing said computer to edit the desired file formed by the block data deciphered by the second computer readable program code means to obtain editing data indicating an editing made in the desire file;

fourth computer readable program code means for causing said computer to encipher the editing data obtained by the third computer readable program code means, in units of blocks by using a prescribed cipher key, to obtain enciphered editing data; and

fifth computer readable program code means for causing said computer to transmit the enciphered editing data obtained by the fourth computer readable program code means to the file management server device, such that the file management server device manages the desired file according to the enciphered editing data received from the client device and the block identification information for each block data.