RGB Intensity Based Variable- Bits Image Steganography 2008 IEEE Asia-Pacific Services Computing Conference (APSCC 2008) 1 st 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 & Engineering King Fahd University of Petroleum & Minerals (KFUPM) Dhahran, Saudi Arabia
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 2/21
The Problem Hide (embed) a file within another file Data File Cover File Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 3/21
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 4/21
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 5/21
The Idea Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 6/21
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 7/21
Algorithm Outline 1 2 3 4 R G B 82 45 91 82 45 91 82 45 91 01010010 45 01011011 01011101 45 01011011 The 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) 93 45 91 5 01011101 45 01011010 Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 8/21
Example 50 X: 1 Y: 1 RGB: 255, 255, 255 X: 215 Y: 63 RGB: 33, 8, 4 100 150 200 50 X: 1 Y: 1 RGB: 254, 255, 255 X: 215 Y: 63 RGB: 33, 8, 115 250 100 300 150 50 100 150 200 250 300 200 Up to 7 bits have been modified 250 300 50 100 150 200 250 300 Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 9/21
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 10/21
Experimentations Cover Image Data File Image size: 640 X 480, Bit depth: 24 No of pixels = 307200 Image size: 150 X 117, Bit depth: 24 Data length = 150896 bits Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 11/21
Experimentations 50 100 150 200 250 300 350 400 450 100 200 300 400 500 600 Pixels utilized: 50939 Constant 3 bits per channel Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 12/21
Experimentations 50 100 150 200 250 300 350 400 450 100 200 300 400 500 600 Pixels utilized: 41061 3/4 bits per channel Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 13/21
Experimentations 50 100 150 200 250 300 350 400 450 100 200 300 400 500 600 Pixels utilized: 38364 Constant 4 bits per channel Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 14/21
Experimentations 50 100 150 200 250 300 350 400 450 100 200 300 400 500 600 Pixels utilized: 35791 4/5 bits per channel Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 15/21
Histograms 8000 7000 6000 5000 4000 3000 2000 1000 0-50 0 50 100 150 200 250 300 Histogram of Red channel: cover image 8000 7000 6000 5000 4000 3000 2000 1000 0-50 0 50 100 150 200 250 300 Histogram of Red channel: stego file Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 16/21
Histograms 7000 6000 5000 4000 3000 2000 1000 0-50 0 50 100 150 200 250 300 Histogram of Green channel: cover image 7000 6000 5000 4000 3000 2000 1000 0 50 0 50 100 150 200 250 300 Histogram of Green channel: stego file Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 17/21
Histograms 6000 5000 4000 3000 2000 1000 0-50 0 50 100 150 200 250 300 Histogram of Blue channel: cover image 6000 5000 4000 3000 2000 1000 0-50 0 50 100 150 200 250 30 Histogram of Blue channel: stego file Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 18/21
Comparison Technique No 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 3 or 4 4 4 or 5 50939 41061 38364 35791 16.58% 13.37% 12.49% 11.65% Pixel Indicator 2 + 2 3 + 3 4 + 4 77578 59051 44687 25.25% 19.22% 14.55% Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 19/21
Comparison: High Capacity 50 Our Algorithm 100 150 200 50 100 150 200 250 300 Cover Image Pixels utilized: 16.5% Constant 3 bits per channel Pixel Indicator Algorithm Data File Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 20/21
Summary New idea in image based steganography Variable-bits per channel High capacity algorithm Secure Random indicator sequence Presented at APSCC 2008 in Taiwan, by Adnan Gutub, from KFUPM, Dhahran. Saudi Arabia 21/21