Steganography is the art of hiding information in ways that prevent detection of hidden messages. The goal is to conceal the very existence of a message by hiding it within an envelope or wrapper, such as a digital image, audio file, or text document. Modern steganography techniques embed secret data by making minimal changes to the cover file such that the hidden message cannot be perceived by human senses or computer analysis. Steganography has applications for anonymous communication, reinforcing cryptography, and avoiding third party snooping.

1. The “Keys” to the Kingdom
Presented By:
Mustahid ali

2. Contents
Communication?
What is cryptography?
What is steganography?
Steganography in digital images

3. Introduction
Communication has always been the need for the social system we live in, the primitive
man use designs, sounds and later on developed the art of speaking and writing
languages, with the purpose of communicating efficiently. And today we find ourselves
surrounded by the jargon of internet which is one of the most efficient and fastest means
of communication throughout the globe.Whenever there is a communication link there
has always been a “Recipient” for whom the message is meant and a “Sender” who is
sending the message. But as is always the case there is a third person called “The
Miscreant” or the “Intruder” trying to intercept the message or block it before it reaches
destination. Ancient Greeks and other civilizations used many forms of simple
techniques to evade the detection of message by hiding it or making it unreadable.
Examples are:
• Tatoos on scalp
• Dots on top of ‘i’ and ‘j’
• Deliberate misspellings or Error
• Writing with invisible ink

4. Cryptography:
It is the process of converting the message into an unreadable format. A simple method
is to convert the text into binary (based on ASCII value). Now using a key known only
to the sender and recipient we can XOR the data. This is known as a XOR cipher.
Ciphertext := Plaintext (XOR) Key
Plaintext := Ciphertext (XOR) Key
The output would have an unreadable format like the one below:
LDPKD YLQJD JUHDW WLPHK HUHLQ
To an intruder this unreadable or meaningless message will raise alarm and arouse
suspicion,provoking him to decrypt the message or block it from reaching the
destination. In either case the sender being the loser.

5. Steganography
In Greek steganos means “covered” graphie means “writing”.
The art of hiding information in ways that prevent detection of hidden
messages.

6. Steganography:
It is the art of hiding information in ways that prevent detection of hidden messages. The
goal of steganography is to conceal the very existence of a message being transmitted.
The idea is to hide the secret message in an “envelope” or “wrapper”. The envelope may
be a text file, an image or a sound file.
• embed text in text/images/sound files
• embed image in text/image/sound files
• embed sound in text/image/sound files
The stegnosystem consists of a cover medium in which the message is hidden based
upon a secret key which is known only to the sender and receiver. The Stego-data output
from the system has no visible distortion (in case of image) or audible distortion (in case
of audio) and appears to be the same as the cover. Any output which shows firsthand
distortion violates the goal of steganography and cannot be used for secret
communication.

7. Key

8. Goals of Steganography
Communicate secretly
Mike wants to send a message to Bob without Willie knowing about it.
Idea is to hide the secret message in an “envelope” or
“wrapper”.
Message must not alter the wrapper appreciably.

9. Medium supported
What to hide
– Texts
– Images
– Sound
• How to hide
– embed text in text/images/sound files
– embed image in text/image/sound files
– embed sound in text/image/sound files

10. Hiding in Text:
Apparently neutral’s protest is thoroughly discounted and ignored.
Isman hard hit.Blockade issue affects pretext for embargo on byproducts, ejecting suets and vegetable oils
• Hidden Message
- Pershing sails from NY June 1

11. Information Hiding in Images:
(Least Significant Bit method)
Data to be inserted: character ‘A’: (10000011)
The pixels which would be selected for holding the data are chosen on
the basis of the key which can be a random number.
Ex:
00100111
11101001
11001000
00100111
11001000
11001000
00100111
11101001
11101001
Embedding ‘A’
00100111
00100110
11001001
11101000
11001000
00100111
11001000
11101000
11101001

12. TOP SECRET
+
=
8-bit (256 grayscale)
images.
Courtesy: http://www.citi.umich.edu/u/provos.html

13. Sacrificing 5 bits of cover to carry 5 bits of
secret image
Courtesy: http://www.citi.umich.edu/u/provos.html

14. Stegano-system criteria
Cover data should not be significantly modified i.e
perceptible to human perception system.
Distortion cannot be eliminated so error-correcting codes
need to be included whenever required
The cover Media should be large enough to accommodate
the data to be embedded
Embedded data should be immune to modifications to
cover.

15. Future Aspects of
Stegnography:
- Genome Steganography: Encoding a hidden message in a strand of human
DNA.
- Hiding in the disk space: Hiding the data in unused or reserved space
- Hiding in network packets: Hidden in packets transmitted through the
Internet.

16. Modern day applications
Anonymous communication
Security reinforcement layer to cryptography
Defence
Avoid third party snooping

17. Conclusion
Stegnography has its place in the security. On its own, it won’t serve
much but when used
as a layer of cryptography, it would lead to a greater security.
- Far fetched applications in privacy protection and intellectual
property rights protection.
- Research is going on in both the directions
a. One is how to incorporate hidden or visible copyright information
in various
media, which would be published.
b. At the same time, in opposite direction, researcher are working on
how to detect
the trafficking of illicit material & covert messages published by
certain
outlawed groups