Hend Abdul Amir Hadi Yeqeen Salah Hameed Safa Hamid Mahmood Makki J. Radhi

71 Pages·2013·2.63 MB·English

Republic Of Iraq
Ministry Of Higher Education
And Scientific Research
University Of Baghdad
College Of Science
Department Of Computer Science

A project is submitted to the department of computer
science, college of science, university of Baghdad in
partial fulfillment of the requirements for the degree of
B.Sc. in computer science

Hend Abdul Amir Hadi
Yeqeen Salah Hameed
Safa Hamid Mahmood

Makki J. Radhi

May_2008

 Chapter One, INTRODUCTION TO STEGANOGRAPHY

1.1 Introduction 1
1.2 History of Steganography 4
1.3 Steganography Terms 4
1.4 Steganography in Text 4
1.5 Steganography in Audio 5
1.5.1 Audio Environments 6
1.5.2 Digital representation 6
1.5.3 Transmission medium 6
1.5.4 Methods of Audio Data Hiding 7
1.5.4.1 Low-bit encoding 7
1.5.4.2 Phase coding 7
1.5.4.3 Spread spectrum 8
1.5.4.4 Echo data hiding 9
1.6 Techniques for steganography in image 10
1.7 Steganalysis 11

 Chapter Two, IMAGE DETAILS

2.1 What is a .BMP? 12
2.2 Palette bitmaps 12
2.3 Writing bitmaps 13
2.4 Image types 14
2.5 Image Quality Computation 16

 Chapter Three, Description of the Project

3.1 Project Description 19

3.2 Text in Image 20
3.2.1 Load Cover Image 21
3.2.2 Input a message 22
3.2.3 Hide the Message 23
3.2.4 Extract the Message 24
3.3 Image in Image 25
3.3.1 Load cover Image 26
3.3.2 Load Data Image 27
3.3.3 Hide Data Image 28
3.3.4 Extract Data Image 29
3.4 Audio in Image 30
3.4.1 Load cover image 31
3.4.2 Load audio file 33
3.4.3 Hide audio the file 33
3.4.4 Extract audio the file 34

 Chapter Four, Algorithms

4.1 Text In Image Algorithms 35
4.1.1 Hiding Algorithm 35
4.1.2 Extracting Algorithm 36
4.2 Image In Image Algorithms 37
4.2.1 Hiding Algorithm 37
4.2.2 Extracting Algorithm 39
4.3 Audio In Image Algorithms 40
4.3.1 Hiding Algorithm 40
4.3.2 Extracting Algorithm 42

 Chapter Five, Practical Part

5.1 Main Form 43

5.2 Text in Image Form 43

5.3 Input Message Form 49
5.4 Image In Image Form 51
5.5 Audio In Image Form 59
Data hiding has always been necessary. Encryption is a method
used for most data communication in modern times but
steganography has been used for years and is still being used
to this date. Steganography has many different methods for
achieving the same goal. There are also many reasons why
steganography is the best choice for hiding specific data.
Steganalysis is a process used to discover steganography in
documents and is used in two different methods of attack.
Chapter One, An introduction to Steganography
1. INTRODUCTION

STEGANOGRAPHY : is the practice of hiding private or sensitive
information within something that appears to be nothing out of the
usual. Steganography comes from the Greek words Steganós (Covered)
and Graptos (Writing).

Steganography, the art of hiding messages inside other messages, has
until recently been the poor cousin of cryptography. Now, it is gaining
new popularity with the current industry demands for digital
watermarking and fingerprinting of audio and video.
What are watermarking and fingerprinting? Through the use of
advanced computer software, authors of images, music and software
can place a hidden ``trademark'' in their product, allowing them to
keep a check on piracy. This is commonly known as watermarking.
Hiding serial numbers or a set of characteristics that distinguishes an
object from a similar object is known as fingerprinting. Together, these
two are intended to fight piracy. The latter is used to detect copyright
violators and the former is used to prosecute them. But these are only
examples of the much wider field of steganography.
In studying steganography in text, we examine three main techniques:
line-shift coding, word-shift coding, and feature coding. Each is
designed to fight illegal distribution of text documents by stamping
some recognizable feature into the text, either by shifting the lines,
shifting the word spacing, or altering characteristics of the letters
themselves. We find that some of these methods are quite strong,
proving resistant to even 10 levels of photocopying.
We also look at some more interesting, alternative methods, such as
using grammar to encode data.
Steganography in images has truly come of age with the invention of
fast, powerful computers. Software is readily available off the Internet
for any user to hide data inside images. The most popular technique is
Least Significant Bit insertion, which we will look at. Also, we look at
more complex methods such as masking and filtering, and algorithms
and transformations, which offer the most robustness to attack, such as
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Chapter One, An introduction to Steganography
the Patchwork method in, which exploits the human eye's weakness to
luminance variation.
The final medium, audio, is first explained through a look at how audio
is stored and transmitted. It is then explored through four main
methods of data-hiding: Least significant bit insertion, phase coding,
spread spectrum coding, and echo hiding. Again, the techniques and
their strengths and weaknesses are examined.
We conclude by finding that steganography offers great potential for
securing of data copyright, and detection of infringers. Soon, through
steganography, all artistic creations, pictures, and songs can be
protected from piracy.
Perhaps when you were a child, you used lemon juice to write text on
paper, and then let the paper dry. Your writing would miraculously
reappear on the apparently blank sheet of paper when you heated it.
Or perhaps when you were older, and were introduced to money, you
noticed the image, or watermark, that would appear on bank notes
when they were held up to the light. Both these types of situations are
examples of steganography, the art of secret writing.
Steganography, from the Greek, means covered or secret writing, and is
a long-practiced form of hiding information. Although related to
cryptography, they are not the same. Steganography's intent is to hide
the existence of the message, while cryptography scrambles a message so
that it cannot be understood.
More precisely, as Kuhn puts it:
``the goal of steganography is to hide messages inside other
harmless messages in a way that does not allow any enemy to
even detect that there is a second secret message present.''

Steganography includes a vast array of techniques for hiding messages
in a variety of media. Among these methods are invisible inks,
microdots, digital signatures, covert channels and spread-spectrum
communications. Today, thanks to modern technology, steganography is
used on text, images, sound, signals, and more.
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Chapter One, An introduction to Steganography
The advantage of steganography is that it can be used to secretly
transmit messages without the fact of the transmission being discovered.
Often, using encryption might identify the sender or receiver as
somebody with something to hide. For example, that picture of your cat
could conceal the plans for your company's latest technical innovation.
However, steganography has a number of disadvantages as well. Unlike
encryption, it generally requires a lot of overhead to hide a relatively
few bits of information. However, there are ways around this. Also, once
a steganographic system is discovered, it is rendered useless. This
problem, too, can be overcome if the hidden data depends on some sort
of key for its insertion and extraction.
In fact, it is common practice to encrypt the hidden message before
placing it in the cover message. However, it should be noted that the
hidden message does not need to be encrypted to qualify as
steganography. The message itself can be in plain English and still be a
hidden message. However, most steganographers like the extra layer of
protection that encryption provides. If your hidden message is found,
and then at least make it as protected as possible.
In the field of steganography, some terminology has developed.
The adjectives cover, embedded and stego were defined at the
Information Hiding Workshop held in Cambridge, England. The term
``cover'' is used to describe the original, innocent message, data, audio,
still, video and so on. When referring to audio signal steganography, the
cover signal is sometimes called the ``host'' signal.
The information to be hidden in the cover data is known as the
``embedded'' data. The ``stego'' data is the data containing both the
cover signal and the ``embedded'' information. Logically, the processing
of putting the hidden or embedded data, into the cover data, is
sometimes known as embedding.
Occasionally, especially when referring to image steganography, the
cover image is known as the container.

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Chapter One, An introduction to Steganography
2. HISTORY OF STEGANOGRAPHY

Through out history Steganography has been used to secretly
communicate information between people.
Some examples of use of Steganography in past times are:
1. During World War 2 invisible ink was used to write information on
pieces of paper so that the paper appeared to the average person as
just being blank pieces of paper.
Liquids such as urine, milk, vinegar and fruit juices were used,
because when each one of these substances is heated they darken and
become visible to the human eye.
2. In Ancient Greece they used to select messengers and shave their
head, they would then write a message on their head. Once the
message had been written the hair was allowed to grow back.
After the hair grew back the messenger was sent to deliver the
message, the recipient would shave off the messengers hair to see the
secret message.
3. Another method used in Greece was where someone would peel wax
off a tablet that was covered in wax, write a message underneath the
wax then re-apply the wax.
The recipient of the message would simply remove the wax from the
tablet to view the message.
3. STEGANOGRAPHY TERMS
Carrier File – A file which has hidden information inside of it.
Steganalysis – The process of detecting hidden information inside of a file.
Stego-Medium – The medium in which the information is hidden.
Redundant Bits – Pieces of information inside a file which can be
overwritten or altered without damaging the file.
Payload – The information which is be the concealed.
4. STEGANOGRAPHY IN TEXT
One problem identified by Brassil and others is the illegal distribution
of documents through modern electronic means, such as electronic mail.
Means such as this allow infringers to make identical copies of
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