2.  Steganography is the art and science of writing
hidden messages in such a way that no one, apart from
the sender and intended recipient, suspects the
existence of the message.
 The word steganography is of Greek origin and means
"concealed writing" from the Greek
words “steganos” meaning "covered or
protected", and ”graphei” meaning "writing".
 Generally, messages will appear to be something else:
images, articles, shopping lists, or some
other covertext.

3.  Media files are ideal for steganographic transmission
because of their large size.
 As a simple example, a sender might start with an
image file and adjust the color of every “100th” pixel to
correspond to a letter in the alphabet, a change so
subtle that someone not specifically looking for it is
unlikely to notice it.

4. The advantage of steganography
over cryptography alone is that messages do not attract
attention to themselves. Plainly visible encrypted
messages—no matter how unbreakable—will arouse
suspicion, and may in themselves be incriminating in
countries where encryption is
illegal.Therefore, whereas cryptography protects the
contents of a message, steganography can be said to
protect both messages and communicating parties.

5.  A steganography software tool allows a user to embed
hidden data inside a carrier file, such as an image or
video, and later extract that data.
 Some common steganography tools are :
a) SNOW
b) S-TOOLS
c) STEALTH
d) HIDE and SEEK
e) PARANOID

6. • Snow steganography also known as “Whitespace
steganography” is used to conceal messages in ASCII
text by appending the white spaces to the end of the
line.
• As spaces and tabs are generally not visible in text
viewers, the message is effectively hidden from casual
observers.
• Snow exploits the steganographic nature of
whitespace.Locating /trailing whitespace in text is like
finding a polar bear in a snowstorm.

7.  The snow program runs in two modes - message
concealment, and message extraction.
 During concealment, the following steps are taken:
Message -> optional compression -> optional
encryption -> concealment in text
 Extraction reverses the process:
Extract data from text -> optional decryption ->
optional uncompression -> message

8.  S-Tools is a program that helps you hide your files and
folders using steganography - it hides your data within
graphics files (BMP, GIF) and WAV files (music) in such a
way that the files are no different from those not
containing any hidden data (that is, the picture can still be
viewed, the music can be listened to).
 Digital files (like *.bmp or *.wav) can be to some extent
modified so that the changes will not affect the quality of
image or sound (i.e. the changes will be virtually
unnoticeable).
 The program not only hides your data within a seemingly
usual file but it enables you to encrypt the hidden data as
well.

9.  S-Tools is somewhat less powerful in that it lacks
features such as the ability to hide data within HTML
and text files, and irrecoverable data deletion.

10. You open up a copy of STools and drag pictures
and sounds across to it.
To hide files you just
drag them over open
sound/picture windows.
You can hide multiple
files in one
sound/picture and your
data is compressed
before being encrypted
then hidden.

11.  Camouflage allows you to hide files by scrambling
them and then attaching them to the file of your
choice. This camouflaged file then looks and behaves
like a normal file, and can be stored, used or emailed
without attracting attention.
 Example, you could create a picture file that looks and
behaves exactly like any other picture file but contains
hidden encrypted files, or you could hide a file inside a
Word document that would not attract attention if
discovered. Such files can later be safely extracted.

12.  For additional security you can password your
camouflaged file. This password will be required when
extracting the files within.
You can even camouflage files within camouflaged
files.les can later be safely extracted.

13.  Steganalysis is the art and science of detecting
messages hidden using steganography.
 The goal of steganalysis is to identify suspected
packages, determine whether or not they have a
payload encoded into them, and, if
possible, recover that payload.
 Steganalysis generally starts with a pile of
suspect data files, but little information about
which of the files, if any, contain a payload.