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

• US 5,835,601 A
• Filed: 03/15/1995
• Issued: 11/10/1998
• Est. Priority Date: 03/15/1994
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Shimbo, Atsushi, Takahashi, Toshinari, Tomoda, Ichiro, Murota, Masao
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Laufer, Pinchus M.
• Application Number:
  US08/404,871
• Time in Patent Office: 1,336 Days
• Field of Search: 380/49, 380/9, 380/29, 380/37, 380/42, 380/3, 380/4, 395/612, 395/617, 395/619, 395/761, 395/792, 707/100, 707/201, 707/203, 707/500, 707/530, 707/49
• 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 2221/2107 File encryption
• 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
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99954 Version 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 converted desired file into the editing procedure data for the latest version of the desired file, and a unit for generating record management information indicating a result of the converted 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; 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, 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 and including insertion data to be inserted into the desired file;

enciphering means for enciphering the insertion data included in the editing procedure data generated by the editing procedure generation means, by using a prescribed cipher key, to obtain enciphered editing procedure data; and

communication means for transmitting the enciphered editing procedure data obtained by the enciphering means to the file management server device;

wherein the file management server device includes;

editing procedure conversion means for converting the enciphered editing procedure data for the desired version of the desired file received from the client device into enciphered 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 enciphered editing procedure data for the latest version of the desired file obtained by the editing procedure conversion means; and

record management means for carrying out a record management of the desired file according to the record management information obtained by the record management information generation means and the block identification Information for each block data.

2. The system of claim 1, wherein the record management means uses record data indicating a relationship between the desired version and the latest version in carrying out the record management of the desired file, and the editing procedure conversion means generates the converted enciphered editing procedure data for the latest version of the desired file by referring to said relationship between the desired version and the latest version indicated by the record data.

3. The system of claim 1, wherein the file management server device has a file managing means for managing each file in a form of a first block data in which an originally created file content is enciphered, a subsequent block data in which difference between a file content before each editing and a file content after each editing is enciphered, and the block identification information attached to each block data which identifies each block data.

4. The system of claim 1, wherein the file management server device has file managing means for managing each file in a form of a latest block data in which a latest edited file content is enciphered, a previous block data in which difference between a file content before each editing and a file content after each editing is enciphered, and the block identification information attached to each block data which identifies each block data.

5. The system of claim 1, wherein the file management server device has file managing means for managing each file in a form of insertion block data in which each content inserted into each file is respectively enciphered, deletion block data in which each content deleted from each file is respectively enciphered, and the block identification information attached to each block data which identifies a creation time and a deletion time of each block data.

6. The system of claim 5, wherein the file management server device has file managing means for managing each block data in a state of being enciphered in units of blocks by an 8 bit CFB mode type cipher scheme, and the enciphering means enciphers the insertion data by the 8 bit CFB mode type cipher scheme.

7. The system of claim 1, wherein the file management server device has file managing means for managing each block data in a state of having at least an insertion data portion of each block data enciphered by a stream cipher scheme, and the enciphering means enciphers the insertion data by the stream cipher scheme.

8. The system of claim 1, wherein the block identification information for the block data resulting from the editing made by the editing means is attached to the record management information in a course of one of record management information generation by the record management information generation means and the record management by the record management means.

9. 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 a file management server device, each file containing a plurality of block data and block identification information for each block data;

making 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, at the client device;

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

editing the desired version of the desired file formed by the block data deciphered by the deciphering step, at the client device;

generating editing procedure data indicating a procedure to obtain an editing made in the desired version of the desired file by the editing step and including insertion data to be inserted into the desired file, at the client device;

enciphering the insertion data included in the editing procedure data generated by the editing procedure data generating step, by using a prescribed cipher key, to obtain enciphered editing procedure data at the client device;

transmitting the enciphered editing procedure data obtained by the enciphering step from the client device to the file management server device;

converting the enciphered editing procedure data for the desired version of the desired file received from the client device into enciphered editing procedure data for a latest version of the desired file, at the file management server device;

generating record management information indicating a result of the editing made by the editing step, according to the enciphered editing procedure data for the latest version of the desired file obtained by the converting step, at the file management server device; and

carrying out a record management of the desired file at the file management server device, according to the record management information obtained by the record management information generating step and the block identification information for each block data.

10. A client device for accessing a server device which manages files, each file containing a plurality of block data and block identification information for each block data, whereby the client device obtains the block data corresponding to a desired version of a desired file managed by the server device, the client device comprising

a deciphering unit for deciphering the block data obtained from the server device, by using a prescribed decipher key;

an editing unit for editing the desired version of the desired file formed by the block data deciphered by the deciphering unit;

an editing procedure generation unit for generating editing procedure data indicative of a procedure to obtain an editing made in the desired version of the desired file by the editing unit and including insertion data to be inserted into the desired file;

an enciphering unit for enciphering the insertion data included in the editing procedure data generated by the editing procedure generation unit, by using a prescribed cipher key, to obtain enciphered editing procedure data; and

a communication unit for transmitting the enciphered editing procedure data obtained by the enciphering unit to the server device.

11. A method for accessing a server device which manages files, each file containing a plurality of block data and block identification information for each block data, the method comprising the steps of:

obtaining the block data corresponding to a desired version of a desired file managed by the server device;

deciphering the block data obtained from the server device, by using a prescribed decipher key;

editing the desired version of the desired file formed by the block data deciphered by the deciphering step;

generating editing procedure data indicative of a procedure to obtain an editing made in the desired version of the desired file by the editing step and including insertion data to be inserted into the desired file;

enciphering the insertion data included in the editing procedure data generated by the generating step, by using a prescribed cipher key, to obtain enciphered editing procedure data; and

transmitting the enciphered editing procedure data, obtained by the enciphering step, to the server device.

12. A computer-implemented 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 accessing a server device which manages files, each file containing a plurality of block data and block identification information for each block data, whereby the client device obtains the block data corresponding to a desired version of a desired file managed by the server device, the computer readable program code means including;

a first computer readable program code that causes said computer to decipher the block data obtained from the server device, by using a prescribed decipher key;

a second computer readable program code that causes said computer to edit the desired version of the desired file formed by the block data deciphered by the first computer readable program code;

a third computer readable program code that causes said computer to generate editing procedure data indicative of a procedure to obtain an editing made in the desired version of the desired file by the second computer readable program code and including insertion data to be inserted into the desired file;

a fourth computer readable program code that causes said computer to encipher the insertion data included in the editing procedure data generated by the third computer readable program codes, by using a prescribed cipher key, to obtain enciphered editing procedure data; and

a fifth computer readable program code that causes said computer to transmit the enciphered editing procedure data obtained by the fourth computer readable program code to the server device.

13. A server device for managing files, each file containing a plurality of block data and block identification information for each block data, wherein a client device accesses the server device to obtain the block data corresponding to a desired version of a desired file managed by the server device, the server device comprising:

an editing procedure conversion unit that converts enciphered editing procedure data for the desired version of the desired file received from the client device into enciphered editing procedure data for a latest version of the desired file, the enciphered editing procedure data being indicative of a procedure to obtain an editing made in the desired version of the desired file by the client device and including insertion data to be inserted into the desired file where the insertion data are enciphered by using a prescribed cipher key;

a record management information generation unit that generates record management information indicative of a result of the editing made by the client device, according to the enciphered editing procedure data for the latest version of the desired file obtained by the editing procedure conversion unit; and

a record management unit that carries out a record management of the desired file according to the record management information generated by the record management information generation unit and the block identification information for each block data.

14. A method for managing files at a server device, each file containing a plurality of block data and block identification information for each block data, wherein a client device accesses the server device to obtain the block data corresponding to a desired version of a desired file managed by the server device, the method comprising the steps of:

converting enciphered editing procedure data for the desired version of the desired file, received from the client device, into enciphered editing procedure data for a latest version of the desired file, the enciphered editing procedure data being indicative of a procedure to obtain an editing made in the desired version of the desired file by the client device and including insertion data to be inserted into the desired file where the insertion data are enciphered by using a prescribed cipher key;

generating record management information indicative of a result of the editing made by the client device, according to the enciphered editing procedure data for the latest version of the desired file obtained by the converting step; and

carrying out a record management of the desired file according to the record management information generated by generating step and the block identification information for each block data.

15. A computer-implemented article of manufacture, comprising:

a computer usable medium having computer readable program code means embodied therein for causing a computer to function as a server device for managing files, each file containing a plurality of block data and block identification information for each block data, wherein a client device accesses the server device to obtain the block data corresponding to a desired version of a desired file managed by the server device, the computer readable program code means including;

a first computer readable program code that causes said computer to convert enciphered editing procedure data for the desired version of the desired file received from the client device into enciphered editing procedure data for a latest version of the desired file, the enciphered editing procedure data being indicative of a procedure to obtain an editing made in the desired version of the desired file by the client device and including insertion data to be inserted into the desired file where the insertion data are enciphered by using a prescribed cipher key;

a second computer readable program code that causes said computer to generate record management information indicative of a result of the editing made by the client device, according to the enciphered editing procedure data for the latest version of the desired file obtained by the first computer readable program code; and

a third computer readable program code that causes said computer to carry out a record management of the desired file according to the record management information generated by the second computer readable program code and the block identification information for each block data.