STEGANOGRAPHY Presented by: Prajwal Shrestha 1NC10EC053 Under Guidance of: Mrs. Bhavya V, Mrs. Roopa G Dept. of ECE Dept of ECE, NCET 1
May 24, 2015
STEGANOGRAPHYSTEGANOGRAPHY
Presented by:
Prajwal Shrestha
1NC10EC053
Under Guidance of:Mrs. Bhavya V,Mrs. Roopa GDept. of ECEDept of ECE, NCET 1
ContentsContents
What is STEGANOGRAPHY?
How it works?
Methodology
Merits and Demerits
Conclusion
What is STEGANOGRAPHY?
How it works?
Methodology
Merits and Demerits
ConclusionDept of ECE, NCET 2
What is STEGANOGRAPHY?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
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
Dept of ECE, NCET 3
How it works?How it works?
Dept of ECE, NCET 4
MethodologyMethodology
Traditional Method Hidden messages on messenger's body hair
Using newspaper articles / want-ads
Hidden messages within wax tablets
Invisible Ink
Traditional Method Hidden messages on messenger's body hair
Using newspaper articles / want-ads
Hidden messages within wax tablets
Invisible Ink
Dept of ECE, NCET 5
Methodology (contd.)Methodology (contd.)
Modern Method Digitally embedding messages in other media, such as:
• Text
• Image
• Audio
Modern Method Digitally embedding messages in other media, such as:
• Text
• Image
• Audio
Dept of ECE, NCET 6
Text SteganographyText 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’
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’
Dept of ECE, NCET 7
Image SteganographyImage Steganography
Dept of ECE, NCET 8
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
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
Noisy Area’s ExampleNoisy Area’s Example
Dept of ECE, NCET 9
LSB Insertion’s ExampleLSB Insertion’s Example
Dept of ECE, NCET 10
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)
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)
Image Steganography (contd.)Image Steganography (contd.)
Simple image steganography by hiding one image into another.
Simple image steganography by hiding one image into another.
Dept of ECE, NCET 11
Audio SteganographyAudio 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
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
Dept of ECE, NCET 12
Audio Steganography (contd.)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
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, 104Dept of ECE, NCET 13
Merit and DemeritMerit and Demerit
Merit:
More secure.
Does not attract any focus.
Demerit:
Complex Process.
Increase in data size can arise suspension.
Merit:
More secure.
Does not attract any focus.
Demerit:
Complex Process.
Increase in data size can arise suspension.
Dept. of CSE, NCET 14
ConclusionConclusion
Hiding Information
Secret among sender and receiver
Has both good and bad aspects
Hiding Information
Secret among sender and receiver
Has both good and bad aspects
Dept of ECE, NCET 15
ReferencesReferences
http://en.Wikipedia.org/wiki/Steganography
http://slideshare.net
http://google.co.uk
http://en.Wikipedia.org/wiki/Steganography
http://slideshare.net
http://google.co.uk
Dept of ECE, NCET 16