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Formatted Text Document Data Hiding Robust to Printing,Copying and Scanning

Speaker:Fanjia Yen

Adviser:Quincy Wu

Date:2008/04/10

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Outline

Steganography ISM (Inter-word space) Modulation of the Inter-word Space Embedding rule Hidden Data Extraction Reference

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Steganography

What to hide Text Images Sound

How to hide Embed text in text/image/sound files Embed image in text/image/sound files Embed sound in text/image/sound files

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ISM (Inter-word space)(1/2)

A space between adjacent words in a text row.

There are nine inter-word spaces in the row.

The actual length of the inter-word spaces in terms of number of pixels. 1 pixel -> 1 bit. For example,”1”for black and “0” for white.

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ISM (Inter-word space)(2/2)

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Modulation of the Inter-word Space(1/2)

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Modulation of the Inter-word Space(2/2) After data embedding:

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Embedding rule(1/2)

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Embedding rule(2/2)

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Hidden Data Extraction(1/2)

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Hidden Data Extraction(2/2)

If ΦA - ΦB >0, bit ‘1’ is extracted. If ΦA - ΦB <0, bit ‘0’ is extracted.

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Reference

http://en.wikipedia.org/wiki/Steganography wikipedia

http://ms11.voip.edu.tw/~eddie/file/Formatted_Text_Document_Data_Hiding_Robust_to_Printing_Copying_and_Scanning.pdf