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Abstract
Communication of data by maintaining confidentiality is a major issue everywhere, so to
increase the security a non – conventional approach called steganography is proposed.
“Steganography” is an art of “hiding data within data” [1,2]. In general, Stego means
“covering” and graphia means “writing”. Combining these two terms gives the meaning of
steganography, i.e. ”covered writing”[2]. It is similar to cryptography with a small
difference; cryptography makes use of scrambling of data techniques whereas
steganography makes use of the carrier file of some type to store the information [6]. It is
easy to capture a cryptographic message but it is not easy to know the steganographic
message. “Steganography’s objective is to transmit a message from one end to the other via
harmless carrier/medium. By making use of this method, the attacks on the message are very
rare because the attacks do not know what the actual message is [2]. Embedion with
steganography will produce much more secure data communication. It can be used for
different types of data formats, of which the most popular are .gif, .txt, .wav, .bmp and .jpeg.
These types of files are called carriers. In general, the most common examples of
steganography are invisible ink, covert channel and microdot [2,6]. This concept is used
everywhere or in any technology to send confidential information.
A new type of steganography approach has been proposed named PowerPoint file
Steganography”. Data hiding is done in the sound/custom animation effects of the
PowerPoint file. To implement this technique, a codebook is designed which contains the
confidential details of the sound effects and the text information that needs to be transferred.
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TABLE OF CONTENTS Abstract ...................................................................................................................................ii
Table of Contents....................................................................................................................iii
List of Figures ........................................................................................................................v
1. Background and Rationale………………………………………………………….….......1
1.1 Steganography………………………………………………………………………….1
2. Carrier Methods………….....................................................................................................2
2.1. Text File Steganography……………………………………………………………...2
2.2. Image Steganography……….......................................................................................4
2.2.1. Least Significant Bit Replacement Technique………………...........................5
2.2.2. Algorithm for LSB…......………………………………..………...…………..6
2.3. Audio Steganography...................................................................................................7
2.3.1. Algorithm for Wavelet Transform……………………………………................8
2.4. Video Steganography……………………………………………………...................9
2.4.1MPEG-4 Technique.…………………………………..……………..………......9
2.5. Animation File Steganography….....……………………..………….………….......11
2.5.1 Animation Code Book…………………………..……….……………........11
2.5.2. Embedding Process…………..…..……....………..………………..…......12
3. Research Objectives...........................................................................................................13
3.1. Data Storage in Sound Effects (PowerPoint Files Steganography)….………..….....13
4. Design…………..………..…………………………………….…………...…….……....14
4.1 Designing Codebook & Software…………….……………………………...………15
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5. Implementation…………..………..…………………………………….……...….....….19
6. Testing & Evaluation…..…..…………………………………….………….......…….….24
6.1 Testing Methodology………………………………………………………………..24
6.1.1 Mapping File…………………………………………………………….24
6.1.2 Testing at Sender Side……………………………………………….…..25
6.1.3 Testing at Receiver Side…………………………………………………27
6.2 Evaluation…………………………………………………………………….……..28
7.Results…………………………………………………………………………………….29
8. Conclusion…………..………..…………………………………….…………...…….….32
9.Future Scope………………………………………………………………………………33
10.References…………..………..…………………………………….…………...…….…34
List of Figures Figure 1.1 Idea of Steganography…………………………………………………..….....2
Figure 2.1 LSB for Image-Steganography………………………………………………..6
Figure 2.2 Wavelet Implementation…..………….……………………………………….8
Figure.2.3 Coding of Objects in MPEG-4…………….....................................…………10
Figure 5.1 Codebook text file…………………………………………….…………..….20
Figure 5.2 Plain PowerPoint file with no hidden data………………………………...…21
Figure 5.3 Entering the confidential data that needs to be embedded……....……….......22
Figure 5.4 Message acknowledgement saying the data is embedded…………………...22
Figure 5.5 Hiding data in PowerPoint file using sound effects……………………..…...23
Figure 5.6 Receiver end displaying the embedded text……………………..……….…..24
Figure 6.1 Animation Codebook………………………………………………………...25
Figure 6.2 Embedding data into PowerPoint File…………………………..…………...26
Figure 6.3 Message Acknowledgement……………………………………………..…..27
Figure 6.4 Retrieved Data……………………………………………………………….27
Figure 7.1 Embed or retrieve the data……….…………….……….……….……….…..30
Figure 7.2 Data Hiding in PowerPoint file…………………………………..……….….30
Figure 7.3 Retrieved Message is displayed…………………………………………...…31
Table 4.1 Sample Code Book…………………………………………………………....16
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1. Background and Rational
1.1 Steganography
Steganography is the art of “hiding data within data”, so this section discusses the details
of data hiding techniques in the carrier medium [1]. Generally, there are two types of
steganographic methods for hiding the data. The first method is Spatial Domain Embedding and
the second method is Frequency Domain Embedding [5]. Spatial Domain Embedding uses the
LSB (Least Significant Bit) method, i.e. least significant bits are used to hide the data. The LSB
selection is done randomly in a noisy area so as to reduce the suspect rate [5]. In Frequency
Domain Embedding, Discrete Cosine Transformation (DCT) and Discrete Wavelet
Transformation (DWT) are well known methods. In DCT, initially the image is split into low and
high frequency components that results in spectral sub-bands [10]. Based on these two methods,
different carrier mediums are used for steganography. The process of steganography is illustrated
in Figure 1.1.
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Alice Bob
Figure: 1.1 Idea of Steganography [1]
2. Carrier Methods
2.1 Text Files Steganography
Text file steganography is the most widely used steganography method. To hide a secret
message in a text file is a tedious task due to the very little data availability. So, it would be hard
to add redundant characters or bits to the content [1, 2]. There are several methods for
accomplishing text-based steganography. The two important methods for hiding information in
text are a) Editing the Text Format and b) Jumbling the Text. In the text formatting method, the
actual message is embedded into a randomly selected text that is later transmitted [6]. The best
example for editing the text format method is “Data Hiding within Data” method [6]. A stream
of text data is considered and some characters are selected in that data, for hiding confidential
information. This confidential information is replaced with the characters in that stream of text
and sent to the receiver so that confidentiality is not violated [1]. The following example
Secret Message
Embedding Medium
Message Embedding Function
Stego message
Message Retrieval Function
Secret Key
Secret Message
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illustrates this [1]:
“Some event can run each text in natural sequence in design effectiveness”
From this text first letter of each word is considered to retrieve the desired output. “Some
Event Can Run Each Text In Natural Sequence In Design Effectiveness”. From this the
hidden/confidential data is “secret inside”.
The text file steganography is arduous considering the amount of time and effort involved
in selecting text [2]. In the “Jumbling method”, all the words or textual data are scrambled so
that the message content is hard to crack. There are some more methods that are available to
implement the text file steganography; one among them is "Semantic Method”. In this method,
some of the words from the input stream of data are replaced with its synonym or by
abbreviating the words or by applying punctuation marks in proper places [13]. The major
advantage of this method is securing information by using Optical Character Recognition.
However, in semantic method very little data is hidden.
There are numerous methods that have been proposed for data storage in text files, some
of them are: Formatting Text Method, Line Shifting method, Word Shifting method and Feature
Specific Encoding method [5]. In Line Shifting method, there is vertical transformation of lines
to some degree (2-3 centimeters). This transformation is done based on the line’s position from
the stationary line, which creates distinct shapes of text. In the Word Shifting method,
“Horizontal Spaces method” and “Distance between Words” methods are used, which is used to
evaluate hidden data. Results from Word Shifting are more reliable than Line Shifting. In Feature
Specific Encoding method, the major goal is to format the text by changing the attributes (i.e.
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length of letters d, b etc...) [1, 13].
2.2 Image Files Steganography
Image files are also used to hide data for communication. An image file is an array of
numbers that constitutes light intensities [1, 3]. In this approach, the data can be hidden in a color
image or a gray scale image. Gray-scale images were given more importance because of their
variation in shades. This will increase the scope for hiding information [3, 5]. In the process of
embedding the image file, the confidential data that should be hidden in the image file is first
embedded using a cryptographic algorithm. Then the embedded data is embedded into the image
file, which in turn results in a stego-image [1, 2]. Then a stego-key is used during the hiding
process to send the image securely to the receiver. After the image is received at the other end,
the receiver will extract the data from the image. In order to extract the message, the receiver
requires a shared secret key. The extraction process detailed is a cryptographic algorithm or a
stego-key approach. To improve this process, message compression can be applied, so that data
security is maintained at a higher degree [2].
Compressing an image produces better results during steganography. There are two types
of image compression techniques: Lossy Compression and Lossless Compression. The Lossy
Compression method has various disadvantages and not an efficient technique. This project
focuses on the Lossless Compression method. It was found that the results produced by the Loss
Less Compression are much better. In the Lossless Compression technique, the originality of the
digital image is maintained. Some of the examples of Lossless Compression are Microsoft’s
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Bitmap, CompServ’s GIF etc. [2]. In Lossless Compression technique, 256 shades of grey for 8-
bitimage sizes are used [1, 2]. There are many other methods for hiding message bits. One of the
efficient methods of storing the message bits is “Least Significant Bit Replacement Technique”
which is one among many techniques used for data hiding.
2.2.1. Least Significant Bit Replacement Technique
All image steganography techniques try to alter insignificant information. Of them, LSB
encoding is the most simple and common approach for embedding data. By altering the least
significant bit, the image quality is not compromised. Hence, this will help in preserving the
confidential information [2, 5]. In this technique, the data that needs to be hidden is embedded in
the least significant bits (LSB) of the pixels of the cover image. This modified image is known as
“stego-image”. Due to the changes in the bytes of the image, there might be some traces of
isolated pixels if the pixel location was uniform. Hence, proper care should be taken while the
cover image is selected [5]. The most important factor that should be considered while selecting
a covered image is that the image should be a composition of large amounts of small details [2].
While storing the data using 24-bit image, 3 bits can be stored in each pixel. The green,
blue and red color components were represented in bytes [5]. For example, if a 24-bit color
image is considered and 3 pixels were selected as shown in Figure 2.1
(00101111 01010100 11011000)
(11001000 11111100 11011000)
(00110111 00010111 01011011)
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If a character “A” holding a binary value 10000001 is inserted, the following results are
produced.
(00101111 01010101 11011000)
(11001001 11111100 11011001)
(00110111 00010111 01011011)
So from the example, the letter “A” is embedded into the first 8 bytes, which in turn
modifies 3 bits.
Figure: 2.1 LSB for Image-Steganography [3]
2.2.2. Algorithm for LSB
The following are the sequence of steps that were followed to hide the data [5]:
Step 1: Actual image and the data to be hidden were read.
Step 2: n bits shift operation was performed
Step 3: Shift operation was performed for the cover image with 11110000 so that
MSB’s were set to 0
Step 4: After the shift operation both are bitored.
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This results in changes to the n LSB bits and hence the data or the confidential image is
stored into the cover image [5]. An additional functionality (hiding the bit in a pixel) to the
existing LSB method can be used to make the data more secure. In order to do this, the pixel is
made to satisfy some minimum conditions that are stated as follows, 1) Adjacent neighbor’s
brightness variance is made to be very high or very low or else the pixel will be skipped [3, 5].
Hence these tests were passed by the pixel. This process is done so that the analyst can know
about the pixels. 2) During this process if any of the pixels does not pass the tests the pixel
retains its original value. 3) Soon after the stego-image is received the original image should be
destroyed so that the attacker cannot track the hidden information [5].
2.3. Audio Steganography
Many techniques were proposed in order to perform steganography in audio files
amongst which, LSB (Least Significant Bit) method is the most widely used method [2, 3, 5].
Another method named “Lifting Wavelet Domain” is used for hiding in the audio files [1]. The
pseudo-noise is embedded so that the security factor can be improved. In this technique, the
wavelet is placed in the fifth resolution so that the output is a string, which consists of six sub-
bands (CA1, CD1, CD2, CD3, CD4, and CD5) as shown in Figure 2.2 [4]. Every sub-band
belongs to a specific resolution level. From the above sub-bands it is determined that, to
calculate the fifth level transform; the first level transform should be calculated first so that CA1
and CD1 coefficients are determined [4]. For the next phase, the transformation for CA1
coefficients is performed. Hence this procedure is followed to generate all the coefficients. After
the coefficients are generated, a check is performed to find if there are any strings that are left
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over in the lower level and then those are also transformed until the string results in fifth
resolution level [4].
Temporal signal
CA1 CD1
CA2 CD2
CA3 CD3
CA4 CD4
CA5 CD5
Figure.2.2 Wavelet Implementation [4] 2.3.1. Algorithm
Here are the steps that are implemented for hiding data [5]:
1) Fifth level transforms are applied on discrete samples and are filtered to produce integer
coefficients. Threshold value is computed with the integer coefficients.
2) Now the steam of string is jumbled by random number generator and hidden with secret key.
3) The String is replaces based on the obtained threshold value.
Finally an inverse LWT is performed. Then the coefficients are converted into time
domain to produce a time stego signal [8].
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2.4. Video Steganography
Even though image based steganography is widely used, it still has certain limitations. In
an image only little information is stored, but a video that is composed of images and audio,
stores huge volumes of data [1, 2]. As most of the video steganographic techniques are lossy,
they are not useful for document hiding. So, a new digital video steganographic technique
(MPEG-4) is proposed that consists of new video structures [7]. This technique increased the
security of the document files without any loss of information.
In this approach, the multimedia data is coded based on objects. Combination of the
elements such as text, audio, video, images or individual is considered as an object [10]. Hence
these objects are known as audio-visual objects.
2.4.1. MPEG-4 Technique
This technique makes use of parallel data structures and MPEGLets, which provide
security and huge storage capacity respectively. It is less complex when compared to other
techniques of digital video steganography [7]. In this technique, a scene is created based on
objects that are present in the specification list of each component and based on the temporal
relations it possesses. Based on these objects, the scene events are described [7]. In this
approach, the text is coded, which is hidden in a MPEG-4 video. MPEG-4 elementary streams
are produced using Java jargon. After this process, MP4Box software is used to synchronize the
MPEG-4 objects and to multiplex them into single video bit stream [7]. As shown in the Figure
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2.3
Figure 2.3 Coding of Objects in MPEG-4 [4]
The following is the mechanism, which is under progress during data hiding in MP4Stego
technique [7].
1) |S| = |C| + 1/3 |D| [7]
Where S= Stego object size
C= Cover object size
D= Document size
The main aim of MPEG-4 technique is to increase the information secrecy, provide
authentication and integrity while the documents are accessed [7, 10]. Hence this reduced the
chance of detecting the messages hidden by the MP4Stego.
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2.5. Animation Files Steganography
Another novel approach of hiding data using PowerPoint files gained importance
recently. In this approach, the data is stored in various animation-timing effects. This approach
uses, animations for applying on text, graphs, and images. Even by the addition of animation
effects the content of the file is not changed [8, 9]. The timing effects and sound effects used for
the animations are used to control the flow of data.
The animation effects can be grouped as: Entrance, Emphasis, Exit and Motion Paths.
Objects are entered with animations in the presentation by making use of entrance effect [8].
Making use of emphasis effect does animation of objects. To make the objects leave the slide,
show an exit effect is being used. Motion paths are used to allow the objects to move around the
slide show [8]. The animation effect is made interactive by having its own timing parameter [9].
2.5.1. Animation Codebook
A codebook is created which consists of all the information related to the effects that are
present in that technique. The codebook will be very helpful to store information in these timing
effects [8, 9]. Next section will state the basic principles required for preparing a codebook.
1) All the three types of animations effects: Entrance, Emphasis/Motion paths and exit should
be re-grouped.
2) At least one-animation effects must be applied for every character of the hidden message [8].
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2.5.2. Embedding Process
This process makes use of two general assumptions and three embedding rules [8].
Asumption1: Both transmitter and the receiver maintains the same animation codebook.
Assumption2: The Embedding animation effect that was applied for the object should
follow the human perception.
Rule 1: Entrance animation is applied if the embedded message object was not on the
slide.
Rule 2: If the entrance effect is used for embedding the object then one can make use of
Emphasis/motion paths or exit animation category.
Rule3: If the embedded object has the emphasis/motion paths animation category, the
only option for that embedded object was exit animation category.
Hence by making use of the animation codebook, assumptions and the rules data is
hidden into the PowerPoint file.
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3 Research Objectives
Based on the present analysis about different carrier media, it was found that the video
file steganography is the most reliable, efficient and expensive method for storing large volumes
of data. But even other methods of steganography are of greater importance based on the usage.
By analyzing different carrier media it is found that PowerPoint file steganography is a new
carrier medium for storing confidential information. Hence, by performing deep analysis on the
PowerPoint files, it is found that there is a possibility of a new approach for storing information
in PowerPoint slides. Section 3.1 illustrates this approach.
3.1. Data Storage in Sound/ Custom Animation Effects
A new technique for storing data in animation files has been proposed recently. In this
technique, the confidential message is embedded or stored in the sound effects of the PowerPoint
files. This can be achieved by collecting all types of sound/custom animation effects that are
present in the PowerPoint files. Based on the type of the sound it is assigned with a character or
number to each sound effect. In this way, a codebook/text file is generated for sound/custom
animation effects and is shared with the sender and the receiver. At the sender side, the message
is hidden into the PowerPoint files by making use of codebook and finally sent to the receiver.
The receiver then retrieves the information from the presentation slides by mapping the sound
effects with the codebook.
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4. Design
As discussed in section 2.5, a codebook implementation that is shared between the sender
and the receiver helps to hide confidential information. Some of the assumptions and rules that
are followed for designing the codebook are [8]:
All the sound effects that are available in the Microsoft PowerPoint are taken into
consideration. If there are not enough sound effects available in the software that are installed in
the local machine, they can be downloaded from the Microsoft official website.
At first a randomly available PowerPoint file is given as input for embedding the data.
Initially, it checks for the number of slides that are available and if the numbers of slides are less
than the actual message length then the program adds additional slides to the file.
Asumption1: Sender and Receiver maintains the same codebook to embed or retrieve the
information.
Assumption2: Using the Microsoft PowerPoint 2010 software the current project was
developed.
Assumption3: To make the project more efficient custom animation effects were also
included
Rule 1: Based on the message size the number of slides should be automatically added.
Rule 2: If one of the sound effects was assigned to any variable it cannot be used again
by any other variable or number.
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4.1 Designing Codebook & Software
A codebook application is designed using .NET technology. All the characters in
alphabet (a-z) and numeric data (0-9) are given as input for this application. Along with these
inputs all the predefined sound/custom animation effects are also submitted as input to the
application. Then a random generator function is called by the application, which assigns a
random sound/animation effect to the individual variable or value. Then this randomly generated
codebook is written to a text file. This would be a major source for data hiding and it needs to be
maintained confidential.
This codebook is shared between the sender and the receiver to exchange the data
confidentially. The sender also sends a PowerPoint file along with the randomly generated
codebook. The PowerPoint file consists of additional information that is not related to the sender
and the receiver. This is to ensure data confidentiality in case of a man in the middle attack. The
PowerPoint file sent by the sender might have irrelevant text but sound/custom animation effects
that are used for that file are important for retrieving the data. There might be a problem that
could be faced when an attack occurs i.e. contamination of data. To safeguard the file from
contamination, any cryptographic technique can be used for additional confidentiality. This
would be the overall idea of transmitting the confidential data. But, to embed the data by
selecting individual sound effect with reference code and to retrieve the data could be a very
tedious task. A tool has been designed for both the sender and the receiver to embed or retrieve
the data.
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This tool is implemented using .NET technology. The sender gives all the input and also
the PowerPoint file to the application. Then the output is the PowerPoint file containing the
embedded data in it. The data that needs to be entered into the file is entered at run time. The
embedded file is then sent to the receiver. The receiver uses application at receiver's end to
retrieve the data. The input for the receiver’s application is the PowerPoint file with the
embedded data and the mapping file containing the codebook. When the receiver clicks on
retrieve button, the secret code will be displayed. Hence by making use of these two tools
(Embedding tool and the Retrieval tool), a secure transfer is performed. In the Table 4.1 is a
sample codebook that was resulted as output.
Table 4.1 Sample Code Book
Sound/Custom Animation Effect Alphabet/ Number
Arrow 1
Applause L
Bomb B
Breeze 2
Camera O
Cash register A
Chime Q
Click U
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Coin 3
Drum roll C
Explosion P
Hammer F
Push T
Suction V
Typewriter 9
Voltage Z
Whose K
Wind D
$CoverRightDown W
$checkboardacross 0
$circleout I
$combveritcal M
$coverright S
$coverdown 8
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$wiperight Y
$wipedown E
$wipeleft J
$wipeup 6
$pushright 5
$pushup R
$pushdown G
$pushleft X
$randombarshorizantal H
$random N
$randombarsvertical 4
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5. Implementation
The major goal of Steganography is to transmit data over a confidential media. Based on
the type of the application and the amount of data that needs to be transmitted carrier media will
be selected. PowerPoint file steganography is a good technique for storing small volumes of data.
In any steganographic technique there are two different phases. One is at the sender phase and
the other is the receiver phase. In the sender side, an embedding algorithm is designed to embed
the data into the PowerPoint file and at the receiver side retrieval algorithm is designed to
retrieve the information. These two (Embedding and Retrieval) algorithms are implemented in a
single application.
When the sender wants to embed the data, the application is deployed and the inputs are
submitted. All the resulted outputs are sent to the receiver. At the receiver end, the application is
deployed and all the outputs that are sent by sender are given as input. When the application is
set to run the secret message will be displayed. The sender side tool and the receiver side tool are
implemented in C#.NET. To deploy this application “Microsoft PowerPoint” driver should be
added to the references. This driver will be helpful to embed the custom animation/ sound effects
into the PowerPoint file randomly.
Creating codebook is another phase in this application. To create this codebook a good
random function is designed. To this random function, both the characters and the sound/Custom
animation effects are given as input and the output is a text file containing the mappings between
the characters and the sound/custom animation effects. To reduce the complexity this part of the
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program is also implemented in the same application (i.e. the embed/retrieval application). When
the application is deployed, the mapping file is generated at first and then the initial screen will
be displayed. The generated mapping file is saved on the desktop. So, whenever the application
is deployed different mapping file will be generated and saved on desktop of the local machine.
Similarly, the PowerPoint file that is given as input is stored in the local machine and taken as
input by the program/application.
In Figure 5.1 it is observed that a codebook generated randomly can contain the
alphabets, numeric data and the names of the sound/ custom effects.
Figure 5.1 Codebook text file
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Sender generates the codebook randomly and passes it as input to the application. A
PowerPoint file with irrelevant data is chosen and passed as input to the application. In Figure
5.2 one can see the PowerPoint file that is given as input.
Figure 5.2 Plain PowerPoint File with No Hidden Data
Then this PowerPoint file is given as input to the application that was developed to
embed the data and then the text or the confidential data is entered in the text field. Figure 5.3
shows that the confidential data is entered into the text field.
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Figure 5.3 Entering the confidential data that needs to be embedded
When the “embed message” button is clicked the data will be successfully embedded into
the PowerPoint file. Figure 5.4 shows the message of acknowledgement.
Figure 5.4 Message acknowledgements saying the data is embedded
During the embedding process the mapping file or the codebook will be scanned. Based
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on the secret message that is entered into the text field, the program will select the exact match of
the letter and related sound/custom animation effect. Then these selected effects are embedded
into the PowerPoint file randomly. i.e. if the related character is assigned with a sound effect
then that sound effect will be assigned to the slide. Figure 5.5 represents the assigned sound
effect to the first slide.
Figure 5.5 Hiding data in PowerPoint file using sound effects
In this way all the characters are embedded into the file by mapping with the
text/codebook that was generated. Finally the PowerPoint file and the codebook text file are sent
to the receiver separately. Receiver makes use of the retrieval part of the application and
retrieves the message. At first these two files are given as input to the program and then clicked
on retrieve then the message is viewed in an alert box as shown in the Figure 5.6.
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Figure 5.6 Receiver end displaying the embedded text
6. Testing & Evaluation
6.1 Testing Methodology
There are three phases of testing in this project they are: testing the mapping file
generation, testing the client side application and receiver side application.
6.1.1 Mapping file
To generate the mapping file a good random function should be used. To have efficient
results the file generated by this application should be unique every time it is generated. There
are many random functions available such as srand, drand etc. By making use of these existing
functions a new random function is created. It is designed in such a way that it will compare with
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already created logs and if there is an occurrence already then it again creates a new file. It is
found that, unique files are generated for every run or program execution. To make this
codebook more efficient, custom animation effects are also included. Figure 6.1 shows the
unique mapping file that is generated by the random function.
Figure 6.1 Animation Codebook
6.1.2 Testing at Sender side
At the sender side to perform embedding, care should be taken to while creating the
mapping file and the PowerPoint file that is given as input. PowerPoint file plays a major role i.e.
the data that is present in the PowerPoint file should be random or irrelevant to the secret
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message. If the information present in the file is related to the secret message it will become easy
for the intruder to crack the information or contaminate the information. So, proper care should
be taken while storing information into the file. Many tests were performed and handled; the
major problem would be when the number of slides is less than the secret message. In this case
extra slides will be added by the program and add some random text to the file. This random text
will be selected from the previous slides of the PowerPoint. It was found that there is no scope
for the intruder to crack the information because; every time a different mapping file is
generated. Figure 6.2 represents the data that is being embedded into the PowerPoint file.
Figure 6.2 Embedding data into PowerPoint File
Another important test case that should be handled is the data limitation. This application
will produce good results when very little data is stored i.e. about 2KB data. If the data exceeds
2KB there may be a chance to attack the data. Figure 6.3 represents the message storage
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acknowledgement.
Figure 6.3 Message Acknowledgement
6.1.3 Testing at Receiver side
In the receiver side proper care should be taken while submitting the inputs to the
application. One should make sure that the data is not contaminated in the middle by cross
checking the PowerPoint slides with the original slides. If it is found that the data is same then
the secret message should be retrieved. If there is some contamination in the data another request
should be made to the send. Figure 6.4 represents the retrieved information.
Figure 6.4 Retrieved Data
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6.2 Evaluation
PowerPoint file steganography in sound effects can be considered as a good technique for
storing the information. But, to improve the data storage capacity (i.e. to embedded more data)
custom animation effects are also used. By making use of both custom animation effects and the
sound effects, the data storage can be extended up to 10kb data. Always the sound effects are
given priority over the custom animation effects during the transition process. Selection of a big
PowerPoint file will solve the problems related to the size of data that needs to be embedded i.e.
if the PowerPoint file size is big large volumes of data can be stored. By making use of this
technique for storing data, it is analyzed that the results produced were promising. This technique
can be best applied during military application. As they require only single word to command the
army. If the size of the data is increased, it was found that there could be a possibility of
contamination of the data. To protect the data any cryptographic technique can be implemented.
By making use of the application that was developed for the sender side, many
codebooks were generated. All the test cases were handled for the sender side and receiver side
application. It was able to accept text related to alphabets and numbers of any range. There is no
limitation to data storage in reality but it would be restricted based on the size of the PowerPoint
files.
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7. Results
The results produced by this tool are very promising. There is no scope for cracking the
data if the codebook is maintained confidentially. There could be a possibility of “Man in the
Middle” attack to contaminate the data. So, to overcome that problem any kind of cryptographic
technique can be used.
When a person would like to transfer very little information confidentially then this
technique could be a better solution. This project is limited only to the alphabets and numeric
data but it can be extended to all types of characters available by including the outside
environment sound/custom effects into the PowerPoint file or downloading these effects from
Microsoft online. In Figure 7.2 it is shown that the data is stored into a PowerPoint file at the
sender side and in Figure 7.3 shows that the information is retrieved at the receiver side. A good
random function is designed in such a way that a unique codebook is generated every time. Both
the sender and the receiver can use the developed application and they can select an option i.e.
whether they want to embed the data or retrieve the data as shown in the Figure 7.1
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Figure 7.1 Embed or Retrieve the data
Figure 7.2 Data Hiding in PowerPoint file
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Figure 7.3 Retrieved Message is displayed
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8. Conclusion
Steganographic techniques are best suited as good carrier techniques for confidential data
transfers. There are different types of steganographic techniques for storing the data based on the
size. But to store little data there are not very good techniques available. So, to maintain
confidentiality and perform a secure communication “PowerPoint” files steganographic
technique can be considered as a better idea. So, the project work proposed a new technique of
storing the data i.e. in the sound/animation effects of a PowerPoint file. It is highly unimaginable
about data existence in sound/custom effects and it could be very hard to crack such data without
having the codebook or the details of the text. A user interface for both the sender and receiver is
designed to make their job easy so that even the novice user can use this application to exchange
the confidential information.
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9. Future Scope
This project is still in the initial stages of development and there is no proof of
concept for the project. Development should be improved to increase the storage capacity.
The major drawback with this application is the storage capacity of the secure data. To
overcome this drawback, audio file steganography and video file steganography can be
implemented on animation file steganography i.e. information is stored in the images,
videos and audio that are present in the PowerPoint file. So, by embedding data into the
images and audio of the PowerPoint file more information or data storage capacity can be
increased up to 1MB.
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10. References [1] Bret Dunbar. “Steganographic Techniques and their usage in an Open-System
Environment,”ACMSANS InstituteInfo.Secur., 2002. [2] J.RKrenn.“Steganography and Steganalysis,” IEEE Info.Assu.Secu., Jan 2004. [3] MathkourHassan, Sadoon A1 Batool and TouirAmeur, “A New Image
Steganography Technique”IEEE WirelessCom.,Ntwrk. And Mob. Cmptn., Oct 2008.
[4] Pooyan M and Delforouzi A. “LSB-based Audio Steganography Method Based onLifting Wavelet Transform,” IEEE International Symposium Sgnl. Proc and Info.Tech.., Dec 2007. [5] Neeta D, Snehal K and Jacobs D. “Implementation of LSB Steganography and
its Evaluation for Various Bits,” IEEE Digi. Info. Mang. pp 173-178, Dec 2006. [6] Shirali-Shahreza M and Shirali-Shahreza S. “Steganography in TeX Documents,” IEEE Intel’s. Sys. Knwldg. Engg. Vol 1, 2008 [7] De Carvalho DF, Chies R and Freire AP. “Video Steganography for ConfidentialDocuments: Integrity, Privacy and Version Control,” ACM 26th International,2008.
[8] Wen-Chao Yang and Ling-Hwei Chen. “A Novel Steganography Method via Various Animation Effects in PowerPoint Files,” ACM LibraryProceeding to Seventh International Conference on Machine Learning Cybernetics, July 2008.
[9] Min-QunJing,Wen-Chao Yang and Ling-Hwei Chen. “A New Steganography Method via Various Animation Timing Effects in PowerPoint Files,”ACM Library Proceeding to Eighth International Conference on Machine Learning Cybernetics,July2009. [10] Andreas Westfeld and Gritta Wolf. “Steganography in a Video Conferencing System,”Institute for Theoretical Computer Science,pp 32-47,Jan 1998. [11] MehdiKharrazi, Husrev T, Sencar, and NasirMemon. “Image Steganography: Concepts and Practice,” Stevens Institute of Technology pp 204-211, Feb 2004. [12] J Dong, W Wang and T Tan. “Multi-class Blind Steganalysis Based on
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Image Run-Length Analysis,” IEEE Assu.Secu.2009 [13] Lingyun Xiang, Xingming Sun, Gang Luo and Can Gan. “Research on Steganalysis for Text Steganography Based on Font Format,” IEEE Info.Assu. and Sec., Third International Symposium, Aug 2007.
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