2. Table of Contents :
• Introduction
• History
• Past use
• Modern use
• Advantages
• Disadvantage
• Steganography vs. cryptography
• Conclusion
• Reference
3. Introduction :
• It is an art of hiding information into any
digital images.
• Only sender and receiver, suspects the
existence of the message.
4. Introduction (contd.):
• It is mixture of two Greek words :
Steganos :- Covered or Protected
Graphei :- Writing
That’s why called Hiding of image or
information or covered writing
• In this we Combine secret image / file with
current image which gives the hidden image.
• The hidden image is difficult to detect without
retrieval.
5. Can be hidden in digital data
• MS Word (doc)
• Web pages (html)
• Executables (exe)
• Sound files (mp3, wav,)
• Video files (mpeg, avi)
• Digital images (bmp, gif, jpg)
6. History Of Steganography :
• Steganographic techniques have been used
from ancient ages.
• The aim of steganographic communication
back and now, in modern applications, is the
same i.e. to hide secret data.
7. Past use :
• Hidden messages within wax tablets — in
ancient Greece, people wrote messages on
the wood, then covered it with wax .
8. Past use (contd.) :
• Hidden messages on messenger's
body also used in ancient Greece.
• In this the message tattooed on the
shaved head.
• Hidden by the hair that afterwards
grew over it, and exposed by shaving
the head again.
• This method has obvious drawbacks,
such as delayed transmission while
waiting for hair to grow and limited
size also.
9. Past use (contd.) :
• During World War II, the French sent some
messages written on the backs of couriers using
invisible ink.
• Hidden messages on paper written by secret inks,
under other messages or on the blank parts of
other messages. Which was latterly retrieve by
either rays or fire , etc.
10. Past use (contd.) :
• Jeremiah Denton repeatedly blinked his eyes in
Morse Code .
• During 1966 televised press conference that he
was forced into as an American POW by his North
Vietnamese captors, spelling out the word, "T-O-
R-T-U-R-E“.
11. Modern Use :
• Modern steganography entered the world in
1985 when personal computer being applied
to classical steganography problems.
• Here we hide our secret data / messages into :
– Digital Images.
– Audio.
– Video , etc.
Here steganography is done with the help
of Steganography tool.
12. Steganography In Images :
• Messages are hidden in background.
• May be anywhere in image.
• Cannot see message in image without encryption.
• This is done with the help of least significant bit (LSB).
14. This is how modern Steganography Works.
Still Problem !!!
Here we go through live example with Steganography tool.
15. Advantages :
• Top Secret – No body apart from sender and
receiver can retrieve message.
• Hide messages like – Images , Audio , Video ,
text , etc.
• Used by Intelligence Bureau – To send their
Secret messages.
16. Disadvantages :
Apart from advantages there are also disadvantage too.
• Used by terrorists : In 9/11 attack al-Qaeda head Bin
Laden used this technology.
• In an image he encoded whole message and then
transport it via e-mail.
Lets see how he done this :
17. Not exact image .
Just for example.
Is it just an image ?????
18. No !!!!!
This is much more than an image.
It holds messages in it.
19. Steganography vs. Cryptography
Steganography Cryptography
Hide the message Does not hide message
Only sender and receiver knows the
existence of message
Everybody knows the existence of
message
End result is stego-media End result is cipher-text
Used from ancient time till modern era Used in modern era
