Forgery Resistant Scrambled Image Watermarking
Priyanka Sharma1, Shiv Kumar2
1Priyanka Sharma,  M. Tech Computer Science, Pursuing , Arya College of Engg & IT, Rajasthan Technical University, Kota, India.
2Prof Shiv Kumar, Computer Science, Arya College of Engg & IT, Rajasthan Technical University, Kota, India.
Manuscript received on September 27, 2012. | Revised Manuscript received on October 06, 2012. | Manuscript published on October 30, 2012. | PP: 204-208 | Volume-2 Issue-1, October 2012.  | Retrieval Number: A0796102112 /2012©BEIESP

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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: Collusion is a mechanism where some secret information shared between many peers is forged to use for illegal purpose. The watermark embedded in an image is the secret information which can be used to claim the originality by its owner. The images delivered to different peers have different watermarks embedded into them. All those malicious attackers can compare the watermarked images to determine the common places where the watermark has been embedded; hence the watermark can be attacked through collusion. So a new technique for watermarking which is collusion resistant has been proposed here. This scheme uses averaged coefficients based discrete cosine transform to embed the watermark at different areas in different images. The main advantage of the scheme is that the image is scrambled before embedding of the watermark and descrambled after embedding. This leads to spreading of the watermarking information throughout the watermarked image and it is very difficult to detect it. The correlation results show that the watermark is very robust.
Keywords: 4 to 8 bit encoding, DCT, Mid Band coefficient, Scrambling, Watermarking.