Document distribution method and document management method

• US 7,506,365 B2
• Filed: 11/22/2002
• Issued: 03/17/2009
• Est. Priority Date: 11/27/2001
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Hashimoto, Shinji, Hirano, Hideyuki
• Primary Examiner(s): Smithers; Matthew B
• Assistant Examiner(s): GERGISO, TECHANE
• Application Number:
  US10/301,784
• Publication Number:
  US 20030105950A1
• Time in Patent Office: 2,307 Days
• Field of Search: 380/399, 715/513, 715/900, 726/5, 726/17, 713/182, 340/5.86
• US Class Current: 726/5
• 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 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures

Abstract

A document distributing method is proposed using access control information separated into invisible data embedded as an electronic watermark and visible data described in a structured document to achieve prevention of unauthorized alteration of document data, authentication thereof, and prevention of unauthorized access thereto. The method has a step of separating access control information into a first access control information and a second access control information, a step of embedding the first access control information into administrative information-enclosing data, a step of setting an administrative identifier for making the administrative information-enclosing data in which the first access control information has been embedded be an information item in the document data, and a step of enclosing, in the administrative identifier, information content of the administrative information-enclosing data and the second access control information for creating the access control information for accessing the document data together with the first access control information.

Claims

1. A method of distributing a structured document in which identifiers are respectively set for a plurality of information items in document data made of digitized data including text data, image data, music data, and/or other digitized data, and information content of each information item is enclosed in each respective identifier, the method comprising:

creating access control information necessary to access the document data and separating the access control information into a first access control information and a second access control information, the first access control information is any one of encrypted data, authentication information, encryption key information, a control program, or distribution channel information;

specifying given data as administrative information-enclosing data and embedding the first access control information into the administrative information-enclosing data;

setting an administrative identifier for making the administrative information-enclosing data in which the first access control information is embedded be an information item in the document data; and

enclosing, in the administrative identifier, information content of the administrative information-enclosing data in which the first access control information is embedded, and the second access control information for extracting the first access control information from the administrative information-enclosing data to create the access control information for accessing the document data together with the first access control information,

wherein the second access control information comprises at least one of range-specifying information specifying the range of unauthorized alteration prevention in the document data, data type-indicating information indicating the type of the digitized data in which watermark data have been embedded, control type-indicating information indicating the type of information of the first access control information, access policy information for digitized data contained in the document data, watermark control information used when converting the first access control information into watermark data, and a data name of the first access control information.

2. The method of distributing a document as set forth in claim 1, wherein the administrative information-enclosing data comprises digitized data including image data or music data, and the first access control information is embedded as visually or auditorily unrecognizable watermark data into the administrative information-enclosing data.

3. The method of distributing a document as set forth in claim 1, wherein the administrative information-enclosing data comprises digitized data including image data or music data, and the first access control information is embedded as visually or auditorily recognizable watermark data into the administrative information enclosing data.

4. The method of distributing a document as set forth in claim 1, wherein the administrative information-enclosing data has a first data portion and a second data portion, each portion comprising digitized data such as image data or music data;

and encrypted access control information in which the first access control information has been encrypted is created and enclosed in the second data portion, and an encryption key information used to create the encrypted access control information is embedded as visually or auditorily unrecognizable watermark data into the first data portion.

5. The method of distributing a document as set forth in claim 1, wherein the first access control information includes at least one of image data, music data, encryption/authentication/signature-related data, and a control program, and has a file format of image data or music data.

6. The method of distributing a document as set forth in claim 1, further comprising a step of creating duplicate information by duplicating the information content enclosed in the administrative identifier and embedding the duplicate information as an electronic watermark into the administrative information-enclosing data.

7. The method of distributing a document as set forth in claim 1, wherein digitized data contained in a predetermined range of the digitized data in the document data are extracted as secret information, digitized data in which the secret information is replaced with other information for display are assigned as the administrative information-enclosing data, and the secret information is enclosed in the administrative information-enclosing data.

8. The method of distributing a document as set forth in claim 7, wherein the secret information is embedded as visually or auditorily unrecognizable watermark data into the administrative information-enclosing data.

9. The method of distributing a document as set forth in claim 7, wherein the secret information is encrypted and is then enclosed in the administrative information-enclosing data.

10. The method of distributing a document as set forth in claim 1, wherein a signature value is computed of digitized data within a predetermined range of the digitized data in the document data, and the signature value is enclosed in the administrative information-enclosing data.