Steganography and Steganalysis. This one is for MY SEMINAR LAB MENTOR.

1. Prepared By- Saurabh Walia
Submitted to- Ms. Neha Kapur
Senior Lecturer (C.S.)

2. Steganography, Cryptography, and
Watermarking
There are two major branches of information hiding, Steganography and
Watermarking
Watermarking: ℗
– Communication in watermarking is the host signal, with the embedded data
providing copyright protection.
– The existence of a watermark is often declared openly.
– Any attempt to remove or invalidate the embedded content renders the host
useless.
Cryptography:
–
–
–
–
Doesn’t conceal the communication.
Scrambles the data to prevent eavesdroppers understanding the content.
Cryptography involves various methods and implementations.
May be considered complementary and orthogonal (unrelated).
Once the presence of hidden information is revealed or even suspected, the
purpose of steganography is defeated.

3. EVOLUTION-:
steganography
cryptography
watermarking

4. History of Steganography
440 B.C. (physical and wax based)
1st and 2nd world wars.(letters)
Modern Times(microdot)

5. Examples-:
Ancient times•
Demeratus sent a warning about a forthcoming attack to Greece by writing it on a
wooden panel and covering it in wax.
•
Histiaeus, who 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.
World War II
Invincible inks
Null ciphers (unencrypted messages):
Apparently neutral's protest is thoroughly discounted and ignored.
Isman hard hit. Blockade issue affects pretext for embargo on by
products, ejecting suets and vegetable oils.
Sent by a German Spy in WWII, by taking the second letter in each word the following
message emerges:
Pershing sails from NY June 1.
Microdot Technology
Shrinking messages down to the size of a dot became a popular method. Since the
microdot could be placed at the end of a sentence or above a j or an i .

6. Introduction-
Art and science of writing hidden
messages
A form of security through
obscurity
No one apart from the sender and
intended recipients suspects the
existence of messages.

7. Terminology-:
Steganalysis
StegoMedium
Carrier/
Cover File
Embedded/
payload

8. Basics of Modern Steganography
fE:
fE-1:
cover:
emb:
key:
stego:
steganographic function "embedding"
steganographic function "extracting"
cover data in which emb will be hidden
message to be hidden
parameter of fE
cover data with the hidden message

9. Text/
document
Video
Types of
Steganography
Audio
Images

10. Steps In SteganographySteganography
Encoding a
message
Decoding a
message

11. Encoding -:
Prepare a
VESSEL
FILE
Stego
Data
Embed the
payload in
cover file.

12. Decoding-:
Payload
Plain
Document
StegoData

13. SteganographyTools-:
Programs
Images files
Audio files
Video files
Document files
DarkCryptTC
BMP, JPG, TIFF,
PNG, PSD, TGA,
MNG
WAV
-
TXT, HTML,
XML, ODT
OpenPuff
S-Tools
MP3, WAV
BMP, GIF
Steg
ImageSpyer G2
3gp, MP4, MPEG1, MPEG-2, VOB,
SWF, FLV
Pdf
Wav
BMP, JPEG, PNG,
TGA
-
-
BMP, PNG,
JPEG, GIF
-
-
-
BMP, TIFF
-
-
-

14. Steganalysis-:
Art and
science of
detecting
hidden
messages.
Just discovers
steganography
Not related
with
decryption of
data.

15. Steganography techniques-:

16. Least significant bit method-

17. LBS Example-
The message"Boss said that
we should blow
up the bridge at
midnight."
encrypted with
mozaiq using
"växjö" as
password.

18. Audio Steganography-:
•
•
•
•
•
•
Watermarking of audio signals is more challenging compared to the watermarking
of images or video sequences, due to wider dynamic range of the HAS in
comparison with human visual system (HVS). The sensitivity of the HAS to the
additive white Gaussian noise (AWGN) is high as well; this noise in a sound file can
be detected as low as 70 dB.
Some commonly used methods of audio steganography are discussed below-.
Least Significant Bit (LSB) Coding : One of the earliest techniques studied in the
information hiding of digital audio (as well as other media types) is LSB coding. In
this technique LSB of binary sequence of each sample of digitized audio file is
replaced with binary equivalent of secret message.
Parity Coding : Instead of breaking a signal down into individual samples, the parity
coding method breaks a signal down into separate regions of samples and encodes
each bit from the secret message in a sample region's parity bit. If the parity bit of a
selected region does not match the secret bit to be encoded, the process flips the
LSB of one of the samples in the region.
Advantage: The sender has more of a choice in encoding the secret bit, and the
signal can be changed in a more unobtrusive manner.
Disadvantage: This method like LSB coding is not robust in nature.

19. Video steganography-:
• Algorithm of hiding
messages
in video files:

20. Users and Applications-:
Cyber
Forensics
Modern
Printers (HP)
Terrorists
Intelligence
agencies
Hackers

21. Future Scope-:
Finding Needle
in a haystack is
a very
cumbersome task.
•So we hope in
future techniques
would be
developed that
gonna detect the
presence of
smallest and tiniest
of sentences in the
Huge text, audio
and video files
effeciently.