1. STEGANOGRAPHY Sibaka Mahapatra Computer Science 3rd Year, Sec-E
… the art of Hiding Information
Sibaka Mahapatra
Computer Science
3rd Year, Sec-E

2. Table of Contents Introduction Working Principle Tools & Techniques
Steganography
History
Classification
Working Principle
LSB Substitution
Injection
Flow Chart
Tools & Techniques
Steganography Tools
Steganalysis Tools
Usage & Future Application
Modern Printers
Water Marking
Future Application
Conclusion

3. STEGANOGRAPHY
Derived from the Greek words, Steganos (Covered) & Grapto (Writing)
Practice of hiding private or sensitive information within something
that is usually not suspected
Steganography in the modern day sense refers to information or a
file that has been concealed inside a digital Picture, Video or Audio file
Science of hiding information in such a way that no one suspects the
information exists
Steganography is usually combined with Cryptography
When information or a file is hidden inside a carrier file, the data is
encrypted with a password. Referred as ‘Steganalysis’

4. “ PERSHING SAILS FROM NY JUNE 1”
HISTORY
Earlier invisible ink was used to write information on pieces of paper
Head of messengers were shaved so, a message could be written on it
Wax tablet was peeled on which message was to be written & refilled
Null cipher sent by the German embassy in World War I
“PRESIDENT'S EMBARGO RULING SHOULD HAVE IMMEDIATE NOTICE. GRAVE SITUATION AFFECTING INTERNATIONAL LAW. STATEMENT FORESHADOWS RUIN OF MANY NEUTRALS. YELLOW JOURNALS UNIFYING NATIONAL EXCITEMENT IMMENSELY.”
(Taking the first letter in each word of message reveals the hidden text.)
“ PERSHING SAILS FROM NY JUNE 1”

5. CLASSIFICATION
STEGANOGRAPHY
PHYSICAL
DIGITAL
NETWORK
PRINTED

6. STEGANOGRAPHY METHODS
WORKING PRINCIPLE
STEGANOGRAPHY METHODS
Substitution
Injection

7. SUBSTITUTION Altering/Replacing The LSB
When files are created there are usually some bytes in the file that aren't
really needed, or are unimportant
These areas of the file can be replaced with the information that is to be
hidden, with out significantly altering the file or damaging it
This allows a person to hide information in the file and make sure that no
human could detect the change in the file
The LSB method works best in Picture files that have a high resolution
and use many different colors, and with Audio files that have different
sounds and are of a high bit rate
It usually does not increase file size, but depending on size of the
information that is to be hidden, the file can become noticeably distorted

8. INJECTION
Injection
Injection is a relatively simple method than altering the Least
Significant Bit (LSB) technique
Injection method involves directly injecting the secret information into
the carrier file
The Payload and Carrier message are directly fed into the specially
designed Stegosystem encoder
The main problem with this method is that it can significantly increase
the size of the carrier file

9. TERMINOLOGY
Carrier File - A file which has hidden information inside it
Steganalysis - Process of detecting hidden information inside a file
Stego-Medium - The medium in which the information is hidden
Payload - The information which is to be concealed
Redundant Bits - Pieces of information inside a file which can be
overwritten or altered without damaging the file

10. FLOW CHART Payload Stegosystem encoder Carrier Channel or Medium KEY
Stegosystem Decoder
Original
Message

11. ILLUSTRATION

12. MATLAB CODE
Hare = imread('arctic_hare.bmp', 'bmp'); F15 = imread('F15.bmp', 'bmp'); n = 4; % Number of bits to replace 1 <= n <= 7 [Stego, Extracted] = LSBHide(Hare, F15, n); figure, imshow(Stego) figure, imshow(Extracted)
where
function [Stego, Extracted] = LSBHide(Cover, Hidden, n) %LSBHide % [Stego, Extracted] = LSBHide(Cover, Hidden, n) % Hide Hidden in the n least significant bits of Cover Stego=uint8(bitor(bitand(Cover,bitcmp(2^n-1,8)),bitshift(Hidden,n-8))); Extracted = uint8(bitand(255, bitshift(Stego, 8 - n)));

13. OTHER TYPES… Parity coding
It breaks the sound signal into areas & then hides the message in the parity bit. If parity does not match, it adjusts LSB of one of the samples to get the required parity.
Spread spectrum
It makes use of the fact that small changes are more difficult for the human eye or ear to detect at high energy levels. The message is hidden in those areas of the carrier file with the greatest energy.
BPCS
It is the most efficient. Embedded data can be over 50% the size of the carrier without affecting quality noticeably.

14. OTHER TYPES Phase coding
It makes use of the fact that the human ear is less sensitive to phase changes than amplitude changes. The following steps are applied:
Break the signal into no. of segments where the segment length equals the message length
Apply DFT to each segment & store phase, amplitudes in an array
Encode message into the phase vectors of the first segment only
Adjust all subsequent segments to preserve relative phase difference
Reconstruct the wave by inverse DFT

15. STEGANOGRAPHY TOOLS… MP3Stego JPHide and JPSeek
Hides information in MP3 files during the compression process. The
data is first compressed, encrypted and then hidden in the MP3 bit stream
JPHide and JPSeek
JPHIDE and JPSEEK are programs which allow you to hide a file in a jpeg
visual image. There are lots of versions of similar programs available on
the internet but JPHIDE and JPSEEK are rather special
BlindSide Cryptographic Tool
Secret messages are passed in a form such that one would not suspect the
message that is being transferred. The Blindside utility can hide files
of any variety, within a Windows Bitmap image (BMP file)

16. STEGANOGRAPHY TOOLS GIFShuffle wbStego StegoVideo
Used to conceal messages in GIF images by shuffling the colourmap,
which leaves the image visibly unchanged. gifshuffle works with all GIF
images, including those with transparency and animation, and in addition
provides compression and encryption of the concealed message
wbStego
A tool that hides any type of file in bitmap images, text files, HTML files or
Adobe PDF files. The file in which you hide the data is not optically changed
StegoVideo
Allows to hide any file in a video sequence. When the program was created,
different popular codec’s were analyzed and an algorithm was chosen which
provides small data loss after video compression. MSU StegoVideo can be
used as VirtualDub filter or as standalone .exe program, independent from
VirtualDub

17. STEGANALYSIS TOOLS StegAlyzerAS StegAlyzerSS
Capability to scan the entire file system, or individual directories, on suspect
media for the presence of Steganography application artifacts. Can perform
an automated or manual search of the Windows Registry to determine
whether or not any Registry keys or values exist that can be associated with
a particular Steganography application
StegAlyzerSS
Capability to scan every file on the suspect media for the presence of
hexadecimal byte patterns, or signatures, of particular Steganography
applications in the files.
Digital Invisible Ink Toolkit
Provides a simple Java-based Steganography tool that can hide a message
inside a 24-bit color image so that knowing how it was embedded, or
performing statistical analysis, makes it easy to find the concealed info.

18. APPLICATION Modern Printers Digital Watermarking e-mail Spam
Steganography is used by leading manufacturers in digital & laser
printers, including HP and Xerox. Here, tiny yellow dots are added to
each page. The dots are barely visible and contain encoded printer
serial numbers, as well as date and time stamps.
Digital Watermarking
Steganography is used for digital watermarking, where a message is
hidden in an image so that its source can be tracked or verified.
Spam
messages is encrypted steganographically. Coupled with
the "chaffing and winnowing" technique, a sender gets messages
out and cover their tracks all at once.

19. FUTURE APPLICATION Alleged use by terrorists
An example showing how terrorists may
use forum avatars to send hidden messages.
This avatar contains the message "Boss said,
we should blow up the bridge at midnight."
encrypted with
using "växjö" as password.
Alleged use by intelligence services
In 2010, the FBI revealed that the Russian foreign intelligence service
uses customized steganography software for embedding encrypted
text messages inside image files for communicating with illegal agents
stationed abroad.

20. CONCLUSION
Steganography is the art of hiding sensitive data without generating
unnecessary curiosity and suspision among foreign party
Steganalysis is the technique to detect Steganography
The research to device strong steganographic and steganalysis technique
is a continuous process
With proper usage Steganography can prove to be the ultimate solution
to information hidding.On the contrary, its misuse is devastating and
unthinkable.

22. THANK YOU ALL Sibaka Mahapatra Computer Science 3rd Year, Sec-E
… for your Patient Hearing
Sibaka Mahapatra
Computer Science
3rd Year, Sec-E