Transcript
Steganography Part-1 H E E T H E S H V H A V L E B M S C O L L E G E O F E N G I N E E R I N G
Steganography
Hiding messages within other files Like images, audios, videos, webpages…
Cryptography Hiding the meaning of messages
Plain Text: Welcome to Steganography Part 1
Cipher Text: jrypbzr gb fgrtnabtencul cneg 1
Steganography Hiding the existence of messages
Original Image Stego Image
How it all began…
• Hidden messages within wax tablet • Hidden messages on messenger's body • Invisible Ink • Hiding messages using two (or more)
different typefaces, such as normal or italic.
• Microdots • Use Morse Code by POWs during WW2
Digital Steganography
• Concealing messages within the lowest bits • Pictures embedded in video material • Including data in ignored sections of a file, such
as after the logical end of the carrier file • Misspelling names or words that are popular in
the media in a given week, to suggest an alternate meaning
• Using non-printing Unicode characters • Making text the same color as the background
Image Steganography
LSB Steganography
Why the LSB method?
• Human eye cannot differentiate slight changes in color
• Does not change the size of the file
• Harder to detect than other steganography techniques
Why the LSB method?
Why the LSB method? Image: 100x50
Total: 5000 pixels
1 pixel -> 3 Bytes (R: 1 byte, G: 1 byte, B: 1 byte)
R: 1000 0010 G: 1010 0111 B: 0110 1001
Total of 5000 bits for hiding Or 625 bytes (5000/8)
And this is just using 1 bit from each channel
Original Images
Using 1 Bit
Using 2 Bits
Using 4 Bits
Using 6 Bits
Using 7 Bits
Demonstration
Questions?
Thank You!
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