the most common practice of concealing messages and information within other non-secret text or data.

1. STEGANOGRAPHY
…. A SMART WAY TO HIDE A OBJECT!
PRESENTED BY: PRACHETA BISWAS (16MS1FS032)

2. DEFINITION AND ORIGIN
“The art of hiding messages in such a way that no
one but the sender and the intended recipient
knows about the very existence of the message “
The strength of the staganography is “stealth”
The word STEGANOGRAPHY is derived from the
Greek word “STEGANOS”=covered &
“GRAPHIE”=writing

3. EXAMPLES :
Tattoos on shaved heads
Wax covered tablets
Microdots – shrunken picture
Invisible inks – milks, fruit
juice , urine e.tc

6. HISTORY
The first recorded use of stenography can be traced back to 440 BC when
Herodotus mentions an example of stenography in the histories of
Herodotus.
• Ancient example: one shaved the head of his most trusted slave and tattooed a
message on it. After his hair had grown the message was hidden. The purpose
was to instigate a revolt against the Persians.
During the ‘cold war’ period, US and USSR wanted to hide their sensors in he
enemy's facilities. These devices had to send data to their nations, without being
spotted.
• In October 2001, the New York Times published an article
claiming that Al-Qaeda had used steganography to encode
messages into images and transported these via e-mail and
possibly via USENET to prepare and execute the September
11,2001 terrorist attack.

7. TYPES OF
STEGANOGRAPHY
STEGANOGRAPHY
IN TEXT OR
DOCUMENT
STEGANOGRAPHY
IN VIDEO
STEGANOGRAPHY
IN AUDIO
STEGANOGRAPHY
IN IMAGE

8. TEXT/DOCUMENT STEGANOGRAPHY
 Involves 3 types of coding :
1. LINE-SHIFTING CODING: text lines are
vertically shifted to encode the document
uniquely
2. WORD-SHIFT CODING: codeword are coded
into a document by shifting the horizontal
locations of words within text lines, while
maintaining a natural spacing appearance
3. FEATURE CODING: certain text features are
altered ,or not altered, depending on the
codeword.

9. EXAMPLE OF TEXT STEGANOGRAPHY

10. WORD SHIFTING

11. STEGANOGRAPHY IN IMAGES
 1. IMAGE ENCODING TECHNIQUES:
 Least significant bit insertion
 Masking and filtering
 Algorithms and transformations

12. LSB TECHNIQUE
11010110
01110100 011001101 01110011
01110101

13. HOW TO STEGANOGRAPH AN IMAGE

14. IMAGE COMPRESSION
 Image Compression offers a solution to large
image files.
 Save storage space but have differing effects
on any uncompressed hidden data in the
image.

15. IMAGE COMPRESSION

16. TYPES OF IMAGE COMPRESSION
• HIGH COMPRESSION
• MAY NOT MAINTAIN THE
ORIGINAL IMAGE’S
INTEGRITY
• JPEG FORMAT FILES
LOSSY
• MAINTAINS HE ORIGINAL
IMAGE DATA EXACTLY
• MORE FAVOURED
• BMP, GIF FOMAT FILES
LOSSLESS

17. AUDIO STEGANOGRAPHY
 Messages can be hidden in common audio
formatted files or the audio itself. It is more
difficult process than image steganography.
 Methods :
1. Transmitting a message in the human-
inaudible.
2. Digitally embedding a message into an
audio file.

18. AUDIO STEGANOGRAPHY

20. METHODS OF AUDIO DATA HIDING
Low-bit
Encoding
Echo
Data
Hiding
Phase
Coding

21. LEAST SIGNIFICANT BIT (LSB)
 Prefix message with identifier string
 Embedded 1 bit of the message as every
LSB
 Does not require original audio track to
recover the message

22. STEGANOGRAPHY IN VIDEO
 INJECTION
 SUBSTITUTION
 GENERATION
 TRANSFORM DOMAIN

23. INJECTION
 INJECT DATA INTO REDUNDANT PARTS
OF A FILE
 EXE FILES
 WAV FILES
 LESS SECURE THAN ANY OTHER
TECHNIQUES

24. SUBSTITUTION
 MODIFIES PRE-EXISTING DATA OF THE
CONTAINER FILE
 THE FILE SIZE OF THE CONTAINER
OBJECT IS PRESERVED
 LIMITS THE STEGANOGRAPHIC
CAPACITY OF THE CONTAINER FILE

25. GENERATION
 GENERATES A CONTAINER FILE BASED
ON THE COVERT DATA
 THERE IS NO ORIGINAL CONTAINER FILE

26. STEGANALYSIS
 Steganalysis is the art and science of
detecting a secret communication.
 Hiding a message will most likely leave
detectable traces in the cover medium.
 The information hiding process changes the
statistical properties of the cover, which is a
steganalyst attempts to detect.
 The process of attempting to detect
statistical traces is called STATISTICAL
STEGANALYSIS.

27. TYPES OF ATTACKS USED BY STEGANALYST
A. STEGO-ONLY ATTACK –
B. KNOWN COVER ATTACK –
C. KNOWN MESSAGE ATTACK –
D. CHOSEN STEGO ATTACK –
E. CHOSEN MESSAGE ATTACK –
F. KNOWN STEGO ATTACK –

28. IMPORTANT ASPECTS OF STEGANALYSIS
 DETECTING HIDDEN INFORMATION
 DISABLING STEGANOGRAPHY

29. ADVANTAGES
 DIFFICULT TO DETECT AND ONLY
RECEIVER CAN DETECT
 IT CAN BE DONE FASTER WITH LARGE
NO. OF SOTWARE
 PROVIDES BETTER SECURITY FOR
SHARING DATA IN LAN,MAN AND WAN

30. DISADVANTAGES
 THE CONFIDENTIALITY OF INFORMATIONIS
MAINTAINED BY THE ALGORITHMS, AND IF
THE AGORITHMS ARE KNOWN THEN THIS
TECHNIQUE IS OF NO USE
 PASSWORD LEAKAGE MAY OCCUR AND IT
LEADS TO THE UNAUTHORIZED ACCESS
OF DATA
 IF THIS TECHNIQUE IS GONE WRONG LIKE
HACKERS CAN BE VERY MUCH
DANGEROUS FOR ALL

31. APPLICATIONS
I. CONFIDENTIAL COMMUNICATION AND
SECRET DATA SHARING
II. PROTECTION OF DATA ALTERATION
III. ACCESS CONTROL SYSTEM FOR
DIGITAL DISTURBANCE
IV. MEDIA DATABASE SYSTEMS
V. VISUAL CRYPTOGRAPHY AND
STEGANOGRAPHY TECHNIQUES FOR
SECURE E-PAYMENT SCHEME
VI. IMAGE
STEGANOGRAPHY,COMPRESSION AND
IMAGE MORPHING FOR BANKING

32. STEGANOGRAPH
Y
CRYPTOGRAPHY WATERMARKS
Techniques LSB, spatial,
domain,
Jsteg,outguess
Transposition,
substitution, RSA
Compensated
prediction,DCT
NAKED EYE
IDENTIFICATION
NO, as message is
hidden within the
carriers
YES, as message is
converted in other
way which sough
something is hidden
YES, as actual
image is hiding by
some watermark
CAPACITY Differs as different
technology usually
low hiding capacity
Capacity is so high,
but as message is
long ,it chances to
be decrypt
Depends on the size
of the hidden data
DETECTION Not easy to detect Easier than
steganography
Easier than
steganography
STRENGTH Hides message
without altering the
message, it
conceals information
IMPERCEPTIBILITY High High High
APPLICABILITY Universally Universally Universally

33. THANK YOU