1. Ramya Kuppam Manikyam School of Computing Dr. Todd McDonald Professor
STEGANOGRAPHY
Ramya Kuppam Manikyam
School of Computing
Dr. Todd McDonald
Professor
Sponsored by NSF Grant DUE

2. Cryptography was created for securing the secrecy of communication.
Introduction
Since the rise of the internet, one of the most important fact of information technology and communication has been the security of information.
Cryptography was created for securing the secrecy of communication.
Unfortunately, it is not enough to keep the contents of a message secret, it may be necessary to keep the existence of the message secret. This technique is called steganography.

3. The word Steganography comes from Greek:
What is Steganography?
The word Steganography comes from Greek:
Steganos – Covered or Protected
Graphei – Writing
It is a technique of embedding information into something else for the sole purpose of hiding that information from the casual observer.
For true secrecy, you don’t want anyone to know you are sending a message at all.

4. History of Steganography
The idea and practice of hiding information has a long history.
In histories, a Greek historian shaved the head of his most trusted slave and tattooed the message on the scalp.
When the hair grew back, the slave was dispatched with the hidden message.

5. History of Steganography (Cont..)
One more example would be, a Greek exile in Persia wrote a message on the wood backing of a wax tablet.
He then hid the message underneath a fresh layer of wax.

6. History of Steganography (Cont..)
A more subtle method used during world war II was to use invisible inks.
Organic compounds such as lemon juice is used to write a message and it turned dark when held over a flame.

7. Example for encryption: this is fun gsrh rh ufm
Stego Vs. Crypto
Some people might consider steganography to be related to encryption, but they are not the same thing.
They do have the same purpose which is to hide/protect important information, but with different approach.
Cryptography is a technology used to translate something readable to something unreadable whereas steganography conceals information making it unseen.
Example for encryption:
this is fun
gsrh rh ufm
a b c d e f g h I j k l m n o p q r s t u v w x y z
z y x w v u t s r q p o n m l k j i h g f e d c b a
Encryption
Decryption

8. Stego Vs Crypto (Cont…)
One of the main drawbacks of using encryption is that when you see an encrypted message, you know that it’s an encrypted.
If someone captures a network data stream or an that is encrypted, the mere fact that the data is encrypted might raise suspicion.
The person monitoring the traffic may investigate why and use various tools to try to figure out the message’s contents.
In other words, encryption provides confidentiality but not secrecy.
With Steganography, however, the information is hidden, and someone looking at the image wouldn’t be able to determine if there’s any information within the image.
So, it would be right in front of our eyes, but we wouldn’t even be able to see it.

9. Practical uses of Stego:
Advantages:
For instance, we can store password information on image file on your hard drive or web page.
This technology can be used by military operations to transmit confidential messages.
Disadvantages:
This technology was used by terrorists in 9/11 attack to hide their attack plans, maps and activities in chat rooms, bulletin boars and websites.

10. In text steganography, the message is converted to a English text.
Types of Stego
Today, we are going to do two activities in which Steganography is used.
Text Steganography
Image Steganography
Text steganography:
In text steganography, the message is converted to a English text.
It is in fact English text, consisting of words chosen from English dictionary.
To make it look more innocent, the English text are to be formed in such a way that it has some meaning to the intruder.
Then this text can be sent to the receiver, who can then decode the message.

11. Text Steganography (Cont…)
Historically, null ciphers are a way to hide a message in another without the use of a complicated algorithm. Simplest null ciphers is shown in the classic examples below:
Come see how the swallows fly
to the south island helped by
our fine weather. They locate the
place in the immense ocean by navigating
at night, following the clouds which form around
midnight above the shore.
“Come to our place at midnight”

12. I am married happily in Dallas dated eleventh November.
Text Steganography
Another example of text Steganography:
Magazine editors effectively tackle major economic affairs. The supporting technical associate reviews basic user coupled knowledge solutions.
MeetmeaTstarbucks
“Meet me at Starbucks”
I am married happily in Dallas dated eleventh November.
IamhiDdeN
“I am hidden”
She earned academic laurel. They helped exposing dexterity effectively among league.
SealThedeal
“Seal the deal”

13. “The password is secret”
The supply of game for London is going steadily up. Head keep Hudson, we believe, has been now told to receive all orders for fly paper and for preservations of your hen pheasant’s life.
“The game is up. Hudson has told all. Fly for your life.”
5) The main computer’s password is ‘opennthegate’. Is this a secret entrance?
“The password is secret”

14. Image Steganography
Image Steganography:
A digitalized photograph is stored as an array of colored dots called pixels.
Each pixel typically has three numbers associated with it, one for red, green and blue intensities, and these values often range from each bit is stored as eight bits ( zeros and ones)

15. Image Steganography (Cont…)
The difference of one or two in the intensities is imperceptible, and a picture can still look good if the least significant four bits of intensity are altered 1
128 64 32 16 8 4 2 1
MSB
LSB

16. Image Steganography (Cont…)
For example, the ASCII value of letter ‘M’ is 77
We can hide these 8 bits in a pixel as follows:
A text requires 8 bits per letter. So we can hide more than one letter in a pixel. 1
128 64 32 16 8 4 2 1 1 1 1

17. Image Steganography (Cont…)
In Least Significant Bit image Steganography, the intensities of the pixel (Input Data) are embedded with the bits of the secret text (Hidden data) as follows:
What happens when you alter the Most Significant Bit(MSB) or more than four intensities of a pixel?

18. Image Steganography (Cont…)
These are the images before and after embedding text in a image file:

19. Exercise (Embedding a text file)
Open ‘Notepad’ on your desktop and type a secret message you would like to hide using steganography.

20. Exercise (Embedding a text file)
Save that file on the desktop.

21. Exercise (Embedding a text file)
Open the folder ‘steg-v1.0.0’ on the desktop

22. Exercise (Embedding a text file)
Open the ‘steg’ application:

23. Exercise (Embedding a text file)
Click ‘Run’

24. Exercise (Embedding a text file)
‘Steg’ application looks like the below screenshot:

25. Exercise (Embedding a text file)
Click on ‘file’ > ‘Open JPEG image’

26. Exercise (Embedding a text file)
The image is located on desktop named ‘security’

27. Exercise (Embedding a text file)
This is the image in which the data is to be hidden:

28. Exercise (Embedding a text file)
Click ‘Hide’ > ‘Hide data’

29. Exercise (Embedding a text file)
Open the text file that are you are supposed to embed in this image file:

30. Exercise (Embedding a text file)
You will get a pop up saying the ‘data successfully hidden’

31. Exercise (Embedding a text file)
Save the image file with the hidden text file by clicking on Hide > Save

32. Exercise (Embedding a text file)
The image file is saved in the following destination:

33. Exercise (Extracting the text file)
Click on ‘open JPEG image’ to open the image with embedded text file

34. Exercise (Extracting the text file)
The image is located on desktop > stego > hidden

35. Exercise (Extracting the text file)
Open ‘Extract Data’

36. Exercise (Extracting the text file)
Open the image file which has the embedded text file in it as follows:

37. Exercise (Extracting the text file)
You will get a pop up ‘Data extraction success’. Click ‘OK’

38. Exercise (Extracting the text file)
When you open the folder ‘stego’, the text file which is extracted can be viewed.

39. Conclusion
Steganography is fascinating and effective method of hiding data that has been used throughout history.
Methods that can be employed to uncover such devious tactics, but the first step are awareness that such methods even exist.
There are many good reasons as well to use this type of data hiding, including watermarking or a more secure central storage method for such things as passwords, or key processes.
Regardless, the technology is easy to use and difficult to detect. The more that you know about its features and functionality, the more ahead you will be in the game.

40. “Security is the one career where the sky is the limit ; professionals are limited only by their ambition and their imagination.”