This document discusses steganography, which is the practice of concealing a secret message within another message or file. Modern steganography methods digitally embed messages in text, images, or audio files. The document explains how the least significant bit method works to hide messages in image and audio files by replacing the least significant bits of bytes with message bits. While steganography provides secure communication, it also has the drawbacks of increasing data size and requiring a complex encoding process.

1. STEGANOGRAPHY
Presented by:
Prajwal Shrestha
1NC10EC053
Under Guidance of:
Mrs. Bhavya V,
Mrs. Roopa G
Dept. of ECE
Dept of ECE, NCET 1

2. Contents
What is STEGANOGRAPHY?
How it works?
Methodology
Merits and Demerits
Conclusion
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3. What is STEGANOGRAPHY?
Greek words "steganos“ - covered/protected
"graphei“ - writing
the art or practice of concealing a message, image, or
file within another message, image, or file
Hiding a secret message within a cover-medium in such a
way that others can not discern the presence of the
hidden message
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4. How it works?
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5. Methodology
Traditional Method
 Hidden messages on messenger's body hair
 Using newspaper articles / want-ads
 Hidden messages within wax tablets
 Invisible Ink
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6. Methodology (contd.)
Modern Method
 Digitally embedding messages in other media, such as:
• Text
• Image
• Audio
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7. Text Steganography
today every citizen has naive idea calling a life simple, easy,
magnate, icky, narrow and racy, i say one nature that has right
equally essential as people's right is lifted.
Actual message ‘technical seminar is on third april’
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8. Image Steganography
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Using LSB [Least Significant Bit] Method
 Replaces least significant bits with the message to be
encoded
 Most popular technique when dealing with images
 It is best to use images with “noisy areas” – areas with
ample/enough color variation and without large areas of
solid color

9. Noisy Area’s Example
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10. LSB Insertion’s Example
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An image may have the following three pixels (9 bytes) in it somewhere:
(01010010, 10010110, 10100100)
(10110100, 10010001, 01001110)
(10110110, 00101110, 11010001)
If we wanted to hide [131 or 10000011], we would use/replace the least-
significant bits of each byte:
(01010011, 10010110, 10100100)
(10110100, 10010000, 01001110)
(10110111, 00101111, 11010001)

11. Image Steganography (contd.)
Simple image steganography by hiding one
image into another.
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12. Audio Steganography
Slight changes in audio will be indistinguishable
from the original to the human ear
In Audio, you can use the least-significant bits of
each byte as redundant bits
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13. Audio Steganography (contd.)
 Let’s assume an audio file had the following 8 bytes of data in it somewhere:
180, 229, 139, 172, 209, 151, 21, 104
 In binary, this would be:
10110100-11100101-10001011-10101100-11010001-10010111-00010101-01101000
 If we wanted to hide the byte value 214(11010110), we use the least significant bit from
each byte to hide our byte:
10110101-11100101-10001010-10101101-11010000-10010111-00010101- 01101000
 The changes result in the following bytes, which are so close to -the originals that the
difference will be inaudible:
Modified: 181, 229, 138, 173, 208, 151, 21, 104
Original: 180, 229, 139, 172, 209, 151, 21, 104
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14. Merit and Demerit
Merit:
More secure.
Does not attract any focus.
Demerit:
Complex Process.
Increase in data size can arise suspension.
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15. Conclusion
 Hiding Information
 Secret among sender and receiver
 Has both good and bad aspects
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16. References
 http://en.Wikipedia.org/wiki/Steganography
 http://slideshare.net
 http://google.co.uk
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