1. Steganography
Implementation
SM
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2. Contents
• Introduction
• History
• Steganography v/s Cryptograpy
• Types of Steganography
• Steps Involved in Steganography
• Steganography Techniques
• Digital Images
• Lossy and Lossless Compression
• Advantages
• Negative Aspects
• Applications
• Conclusions
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3. Introduction
• Greek Words:
STEGANOS – “Covered”
GRAPHIE – “Writing”
• Advance security is not maintained by the password protection but it is
gained by hiding the existence of the data, which can only be done by
Steganography.
• Steganography is the art and science of writing hidden messages in such a
way that no one apart from the intended recipient knows of the existence of
the message.
• This can be achieve by concealing the existence of information within
seemingly harmless carriers or cover
• Carrier: text, image, video, audio, etc.
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4. History
• Greeks used it writing message on some material and later covering
it with wax, tattooing messages on bald head, later growing hair to
cover it up.
• In World War II invisible inks were used to write messages in
between the lines of normal text message .
• Currently, cryptography and steganography are used to hide and
send the secret data.
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5. Steganography v/s Cryptography
• Cryptography hides the contents of a secret message from a
malicious people, whereas Steganography even conceals the
existence of the message
• In cryptography, the structure of a message is scrambled to make it
meaningless and unintelligible unless the decryption key is available
• Steganography does not alter the structure of the secret
message, but hides it inside a cover-image so it cannot be seen.
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6. • Cryptography :-
• Steganography :-
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7. Types of Steganography
• Steganography In Text/Documents
• Steganography In Images
• Steganography In Audio
• Steganography In Video
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8. Steps involved in Steganography
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9. Steganography Techniques
• Injection: Injection is quite a simple method which simply involves
directly injecting the secret information into the carrier file.
• Substitution: Replacement of the least significant bits of
information that determine the meaningful content of the original
file with new data in a way that causes the least amount of
distortion.
• Generation: The generation technique, unlike injection and
substitution, requires only a covert file, as it is used to create the
overt file.
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10. Digital Images
• By digital Images we presume to deal with bits that is 0’s and 1’s.
• Digital Images having 24-bit depth color images are selected using
RGB color model.
• The idea is to hide text in image with the conditions that the image
quality is retained along with the size of the image.
• 24-bit BMP is preferred over 24-bit JPEG because it is lossless
compression.
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11. Lossy and Lossless Compression
• File compression software looks for redundancies, and eliminates
those redundancies in order to reduce the size of the file.
• Lossy compression reduces a file by permanently eliminating
certain information. When the file is uncompressed, only a part of
the original information is still there.
• With lossless compression, every single bit of data that was
originally in the file remains after the file is uncompressed. All of
the information is completely restored.
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12. Least Significant Bit Insertion:
• The most common and popular method of modern day steganography.
• Overall image distortion is kept to a minimum while the message is
spaced out over the pixels in the images.
• This technique works best when the image file is larger then the
message file and if the image is grayscale.
• Messages are encoded in LSB of every byte in a image.
• Value of each pixel change slightly.
• Grey scale palettes due to least pronounced shades are recommended.
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13. LSB Implementation
• Take T of binary value 11100110.
To store these 8 bits of character
T, we will require 8 pixels.
• Each bit is then replaced by LSB
of each Image byte
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14. • Example : Insert a word TEXT
- T = 01100010
- E = 01101111
- X = 01101101
- T = 01100010
• Image Bits before
• Image Bits after
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15. 15

16. Why LSB?

17. Detecting Steganography :
• The art of detecting Steganography is referred to as Steganalysis.
• Using different tools like sendsecret, Steganography 8.1 ,
Stegdetect, Hiderman etc.
• Steganalysis does not deal with trying to decrypt the hidden
information inside of a file, just discovering it.
• It is mainly done with comparing the encrypted file with the original
copy.
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18. Detecting Steganography
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19. Detecting By histogram technique :
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20. Advantages
• It is used in the way of hiding not the Information but the password
to reach that Information.
• Messages do not attract attention to themselves i.e difficult to detect.
Only receiver can detect.
• The proposed technique uses LSB to hide data from a pre defined
position agreed between two parties. Same position is only used
once to enhance security.
• Can be applied differently in digital image, audio & video file.
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21. Negative Aspects
• Huge number of data results in huge file size, so some one can
suspect about it.
• In sending and receiving information can be leaked.
• It is Vulnerable to almost all media transformations.
• If this technique is used in a wrong way then this can be very much
dangerous.
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22. Applications
• Confidential communication and secret data storing
• Protection of data alteration
• Used in modern printers
• Protect copyrights, to maintain confidentiality.
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23. Conclusion
• Steganography is in the nascent stage of development.
• The importance of Steganography has not been realized to that stage
where it is preferred over its close rival “Encryption”.
• New techniques are being discovered and implemented. It is analyzed
that time is not far away when its importance would be realized by
organizations in general and the arm forces in particular.
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24. References :-
 http://en.wikipedia.org/wiki/Steganography8
 http://computer.howstuffworks.com/file-compression3.htm
 http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4547669
 http://www.math.ucsd.edu/~crypto/Projects/MaxWeiss/steganography.pdf
 http://www.sans.org/reading_room/whitepapers/covert/steganography-matters-
post-911-world_676
 http://www.scribd.com/doc/49683406/1/Steganography-vs-Cryptography
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25. Thank You!
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