RGB Intensity Based Variable- Bits Image Steganography 2008 IEEE Asia-Pacific Services Computing Conference (APSCC 2008) 1 st International Workshop on.

RGB Intensity Based Variable-Bits Image Steganography

2008 IEEE Asia-Pacific Services Computing Conference (APSCC 2008)1st International Workshop on Multimedia, Information Privacy & Intelligent Computing Systems

December 9-12, 2008, Yilan, Taiwan

Mohammad Tanvir Parvez

&

Adnan Abdul-Aziz Gutub

College of Computer Sciences & EngineeringKing Fahd University of Petroleum & Minerals (KFUPM)

Dhahran, Saudi Arabia

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /212

Outline

The problem Instance Goals

Algorithm Idea Step Examples

Experimentations Visual and statistical analysis Comparisons

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /213

The Problem

Hide (embed) a file within another file

Cover FileData File

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /214

Applications

Hiding copyright info

Avoid snooping

Data encapsulation E.g. explanatory information within X-ray images

Copyright protections

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /215

Algorithmic Goals

Secure Less Distortion

Visual Statistical (like Histogram)

Not guessable Data location

High capacity Not dependent on cover image

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /216

The Idea

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /217

Algorithm: Features

One channel as indicator

Data in one of the other channels

Variable-bits per channel Lower color value – Higher no of bits

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /218

Algorithm Outline

82 45 91

R G BThe Algorithm

1. Chose an indicator

2. Chose the channel

3. Decide no of data bits

- Partition scheme

4. Get & store the data [say

1101]

5. Modify the other channel

(if needed)

82 45 911

82 45 912

01011101 45 010110114

01011101 45 010110105

01010010 45 010110113

93 45 91

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /219

ExampleX: 1 Y: 1RGB: 255, 255, 255

X: 215 Y: 63RGB: 33, 8, 4

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X: 215 Y: 63RGB: 33, 8, 115

X: 1 Y: 1RGB: 254, 255, 255

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Up to 7 bits have been modified

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2110

Expectations

Secure Random indicator sequence

Statistically undetectable Only lower bits are changed

High capacity

How much of these can be achieved?

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2111

Experimentations

Image size: 640 X 480, Bit depth: 24No of pixels = 307200

Image size: 150 X 117, Bit depth: 24Data length = 150896 bits

Cover Image Data File

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2112

Experimentations

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Pixels utilized: 50939 Constant 3 bits per channel

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2113

Experimentations

Pixels utilized: 41061 3/4 bits per channel

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Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2114

Experimentations

Pixels utilized: 38364 Constant 4 bits per channel

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Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2115

Experimentations

Pixels utilized: 35791 4/5 bits per channel

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Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2116

Histograms

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Histogram of Red channel: cover image

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Histogram of Red channel: stego file

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2117

Histograms

Histogram of Green channel: cover image

Histogram of Green channel: stego file

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7000

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Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2118

Histograms

Histogram of Blue channel: cover image

Histogram of Blue channel: stego file

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Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2119

Comparison

TechniqueNo of data bits

per channel (bits)

No of pixels of cover media utilized

(pixels)

No of pixels of cover media utilized (percentage)

Intensity Based

Variable-Bits

3 50939 16.58%

3 or 4 41061 13.37%

4 38364 12.49%

4 or 5 35791 11.65%

Pixel Indicator

2 + 2 77578 25.25%

3 + 3 59051 19.22%

4 + 4 44687 14.55%

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2120

Comparison: High Capacity

50 100 150 200 250 300

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Pixels utilized: 16.5% Constant 3 bits per channel

Our Algorithm

Pixel Indicator Algorithm

Cover Image

Data File

Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia /2121

Summary

New idea in image based steganography Variable-bits per channel

High capacity algorithm

Secure Random indicator sequence