PDF (Portable Document Format) file information embedding and extracting method based on PDF cross reference table

A technology of cross-reference table and file information, applied in the field of PDF file information embedding and extraction based on PDF cross-reference table, to achieve the effect of not easy to find and destroy

Inactive Publication Date: 2012-08-01
SUN YAT SEN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Using the invention to embed information in PDF can effectively solve the problems of PDF copyright authentication and authenticity identification, and the invention has good robustness to the editing behavior of PDF documents

Method used

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  • PDF (Portable Document Format) file information embedding and extracting method based on PDF cross reference table
  • PDF (Portable Document Format) file information embedding and extracting method based on PDF cross reference table
  • PDF (Portable Document Format) file information embedding and extracting method based on PDF cross reference table

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Embodiment Construction

[0047]The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0048] like Figure 4 and Figure 5 As shown, it is a flow chart of a method for embedding and extracting PDF file information based on a PDF cross-reference table in the present invention, and the specific steps of the method are as follows:

[0049] (S1) as Figure 4 As shown, perform hidden information embedding, which is specifically:

[0050] (S11) Read the original PDF file stream.

[0051] (S12) Read in the binary hidden information and encode it to obtain a decimal scrambling sequence, and record the decoding information; the specific steps are:

[0052] (S121) Read the binary hidden information string T to be embedded, according to the segment length Segment the binary hidden information string T to obtain n binary hidden information segments, and the length of the last hidden information segment obtained by segmen...

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Abstract

The invention belongs to the field of multimedia signal processing, particularly relates to a PDF (Portable Document Format) file information embedding and extracting method based on a PDF cross reference table. A new cross reference table added in an added update of a PDF file is used as a carrier of hidden information, and the hidden information is invisibly written at the beginning of file creation, has no any influence on a file display layer, can be transmitted on the internet along with the transmission of the file content, has enough big embeddable capacity and cannot be destroyed due to the transmission or the commonly used document editing behavior. For an attacker, the hidden information is hidden and is not easily found and destroyed. As a method for PDF document authentication, the related authentication information such as an author, a reference and a copyright of the file and the like can be invisibly embedded in the PDF file, and the practicality is provided for copyright authentication and authenticity recognition of the PDF file and the like.

Description

technical field [0001] The invention belongs to the field of multimedia signal processing, and in particular relates to a PDF file information embedding and extraction method based on a PDF cross-reference table. Background technique [0002] In recent years, with the rapid development of network technology, more and more people begin to transmit and obtain information through the Internet. At the same time, new office models such as e-commerce and e-government are being widely used, and more and more administrative and commercial documents such as power of attorney, registration forms, contracts, and invoices are being circulated and transmitted in the form of electronic documents. However, in the open environment of the Internet, malicious acts such as copying and tampering always threaten the copyright ownership of electronic documents, and a large number of copyright theft, illegal transmission, information forgery and other problems emerge one after another. Based on t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F21/24G06F21/10
Inventor 刘红梅李雷
Owner SUN YAT SEN UNIV
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