ELECTRONIC DOCUMENT PROCESSING SYSTEM

• US 20110019816A1
• Filed: 10/06/2010
• Published: 01/27/2011
• Est. Priority Date: 05/29/2008
• Status: Active Grant

• Current Assignee: Fujitsu Limited, PFU Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Limited, PFU Limited (Fujitsu Limited)
• Inventors: Nagashima, Mutsumu, Kuraki, Kensuke, Anan, Taizo, Inami, Yasuharu
• Granted Patent: US 8,873,744 B2
• Time in Patent Office: Days
• US Class Current: 380/28
• CPC Class Codes: G06F 21/608 Secure printing
• 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 2221/2107 File encryption
• CPC Class Codes: G06F 2221/2149 Restricted operating environment
• CPC Class Codes: G06T 1/00 General purpose image data processing
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G09C 5/00 Ciphering apparatus or methods not provided for in the preceding groups, e.g. involving the concealment or deformation of graphic data such as designs, written or printed messages
• CPC Class Codes: H04L 2209/30 Compression, e.g. Merkle-Damgard construction
• CPC Class Codes: H04L 2209/608 Watermarking
• CPC Class Codes: H04L 9/08 Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords network architectures or network communication protocols for supporting key management in a packet data network H04L63/06
• CPC Class Codes: H04N 1/32203 Spatial or amplitude domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/32208 involving changing the magnitude of selected pixels, e.g. overlay of information or super-imposition H04N1/32219, H04N1/32224 take precedence
• CPC Class Codes: H04N 1/4486 using digital data encryption
• CPC Class Codes: H04N 2201/3281 Encryption; Ciphering

Abstract

An electronic document processing system 900 includes a digital image generating unit 15 generating a digital image in a predetermined range of the electronic document; an image encrypting unit 11 generating an encrypted image by converting at least a partial area of the generated digital image; a data encrypting unit 21 generating encrypted data by extracting data contained in the predetermined range in pieces of data organizing the electronic document and encrypting the data; an encrypted data storing unit 22 storing the encrypted data; and an encrypted electronic document generating unit 23 generating an encrypted electronic document by replacing the data contained in the predetermined range in the electronic document with the encrypted image.

Claims

1. An electronic document processing system comprising:

a digital image generating unit generating a digital image defined as an aggregation of pixels in a predetermined range of an electronic document;

an image encrypting unit generating an encrypted image by converting at least a partial area of the digital image generated by said digital image generating unit in a way that uses key information;

a data encrypting unit generating encrypted data by extracting data contained in the predetermined range in pieces of data organizing the electronic document and encrypting the extracted data by use of the key information;

an encrypted data storing unit storing the encrypted data; and

an encrypted electronic document generating unit generating an encrypted electronic document by replacing the data contained in the predetermined range in the electronic document with the encrypted image.

2. An electronic document processing system according to claim 1, further comprising:

an input accepting unit accepting an input of an image encrypting target area becoming an image encrypting target that is designated in an image into which the electronic document is rendered and output; and

an imaging target range specifying unit specifying, as the predetermined range becoming the imaging target of said digital image generating unit, a range including all of elements that at least some portions of a rendered image of the elements are embraced by the image encrypting target area in the render-output image, in the respective elements of the data within the electronic document, on the basis of the image encrypting target area accepted by said input accepting unit.

3. An electronic document processing system according to claim 1, wherein said encrypted data storing unit stores the encrypted data in a way that adds the encrypted data to a header area, a footer area, a comment area or an extended area of the electronic document.

4. An electronic document processing system according to claim 1, wherein said encrypted data storing unit adds the encrypted data by way of steganography, a digital watermark or meta-information of the image to the encrypted image.

5. An electronic document processing system according to claim 1, wherein said image encrypting unit converts an image of the encrypting target area into a processing image by use of key information, and generates the encrypted image containing a converted image having regularity used for specifying an encrypting position on the occasion of decryption by regularly converting pixel values of the processing image.

6. An electronic document processing system processing an electronic document, data of a predetermined range of which is replaced with an encrypted image generated by converting at least a part of a digital image generated with respect to the predetermined range, said system comprising:

an encrypted data acquiring unit acquiring encrypted data generated by encrypting the data in the predetermined range;

a data decrypting unit generating decrypted data by decrypting the encrypted data acquired by said encrypted data acquiring unit in a way that uses key information; and

a decrypted electronic document generating unit generating decrypted electronic document by replacing the encrypted image included in the electronic document with the decrypted data.

7. An electronic document processing system according to claim 6, further comprising:

an encrypted image acquiring unit acquiring the encrypted image from the electronic document;

an image decrypting unit generating a decrypted digital image by decrypting the encrypted image acquired by said encrypted image acquiring unit by use of the key information; and

a decrypted digital image output unit outputting a digital image decrypted by said image decrypting unit in place of the encrypted image when the electronic document including the encrypted image is output for a browsing purpose.

8. An electronic document processing system according to claim 7, wherein said image decrypting unit detects an encrypting position where pixel values of the encrypted image are regularly converted and decrypts the encrypted image into a digital image on the basis of the encrypting position and the key information.

9. An electronic document processing system according to claim 6, wherein said encrypted data acquiring unit acquires the encrypted data from a header area, a footer area, a comment area or an extended area of the electronic document.

10. An electronic document processing system according to claim 6, wherein said encrypted data acquiring unit acquires the encrypted data by way of steganography, a digital watermark or meta-information embedded in the image to the encrypted image.

11. An electronic document processing program making a computer function as:

a digital image generating unit generating a digital image defined as an aggregation of pixels in a predetermined range of an electronic document;

an image encrypting unit generating an encrypted image by converting at least a partial area of the digital image generated by said digital image generating unit in a way that uses key information;

a data encrypting unit generating encrypted data by extracting data contained in the predetermined range in pieces of data organizing the electronic document and encrypting the extracted data by use of the key information;

an encrypted data storing unit storing the encrypted data; and

an encrypted electronic document generating unit generating an encrypted electronic document by replacing the data contained in the predetermined range in the electronic document with the encrypted image.

12. An electronic document processing program for processing an electronic document, data of a predetermined range of which is replaced with an encrypted image generated by converting at least a part of a digital image generated with respect to the predetermined range, said program making a computer function as:

an encrypted data acquiring unit acquiring encrypted data generated by encrypting the data in the predetermined range;

a data decrypting unit generating decrypted data by decrypting the encrypted data acquired by said encrypted data acquiring unit in a way that uses key information; and

a decrypted electronic document generating unit generating decrypted electronic document by replacing the encrypted image included in the electronic document with the decrypted data.