Steganography Method Implementaiton in Computer Science

Abstract

The steganography methods are using to hide data in a cover media. These can be helpful to protect data from unauthorized parties. In the modern world, there are many steganographic methods use in computer science. Steganography methods can be applied to any kind of media source including audio, video, text and image formats.

Full text

Sri Lanka Institute of Information Technology
Cryptography - IE3082
Assignment 1
Mini - Research Paper
Group Members:
Student Registration
Number
Student Name
Contribution
it19184654
K.A.I. Anuradha
• Video Steganography
• Introduction
it19065236
Maddumage M
• Audio steganography
• Abstract
it19183800
I.M.V.V.S.B. Illankoon
• Image Steganography
• Conclusion
it19187860
Kawshan G.L.H.T. A
• Text Steganography
• Prepared the document
it19986418
Bogahawatata L.B.G.D.P.K
• Characteristic of data hiding technique
• Gathered information
Submitted date: 29/09/2021

Steganography in Computer Science
K.A.I. Anuradha
Faculty of Computing
SLIIT
Galle, Sri Lanka
it19184654@my.sliit.lk
Maddumage M
Faculty of Computing
SLIIT
Padukka, Sri Lanka
it19065236@my.sliit.lk
I.M.V.V.S.B. Illankoon
Faculty of Computing
SLIIT
Kurunegala ,Sri Lanka
it19183800@my.sliit.lk
Kawshan G.L.H.T.A
Faculty of Computing
SLIIT
Matara, Sri Lanka
it19187860@my.sliit.lk
Bogahawatata L.B.G.D.P.K
Faculty of Computing
SLIIT
Kandy, Sri Lanka
it19986418@my.sliit.lk
Abstract— The steganography methods are using to hide
data in a cover media. These can be helpful to protect data from
unauthorized parties. In the modern world, there are many
steganographic methods use in computer science.
Steganography methods can be applied to any kind of media
source including audio, video, text and image formats.
Keywords— Steganography, Embedding Data, Information
hiding, cover media, sender, receiver.
I. INTRODUCTION
Steganography is the process of secretly introducing data
into an information resource without altering its perceived
quality. The name 'steganography’ word comes from the
Greek word ‘Steganos’, which means "covert," and ‘Graphia’,
which means "writing" (covert writing). The most well-known
application of steganography is to encase a document within
another one. In most cases, genuine information is not
managed to keep up in its original format when data is
concealed. When a steganography method is done to a media
file its original file format will be altered into an equivalent
format as original, as a result, another file is hidden inside it.
II. EVALUATION
A. Types in Steganography
1) Text
In most instances, hiding data in the text has a limited
capacity. Text Steganography uses general techniques
including the number of tabs, white spaces, capital letters, and
every nth letter of a word as a hiding mechanism. A bit can be
concealed at the end of every phrase in a basic Word
processor with fixed-size spaces by adding 1 or 2 spaces to
the message, where one space represents a concealed 0 and
two spaces represent a hidden 1.
Text steganography can be done as Selective Hiding (SELH),
HTML Web Pages (HWP), Hiding Using Whitespaces
(HUW) and Semantic Hiding (SEMH).
There are different types of text steganography techniques,
[1] [2]
Syntactic Method - To hide bits 0 and 1, use punctuation
characters including a comma "," full stop ". and more.
Line Shifting Method – By producing a unique text shape,
the text line is vertically shifted to some degrees.
Word Shifting – Data is hidden by shifting the words
horizontally.
Abbreviation – The text message contains several bytes of
data hidden.
Synonym Method – To hide the data, certain words and their
synonyms are utilized.
Word Spelling – In English writing, This method used to
hide data.
Method
Advantages
Disadvantages
Syntactic
The quantity of data
required to hide the
approach is
minimal.
Easily can be
found hidden data
by small readers.
Line Shifting
Only suitable for
printing text; OCR
(character
recognition) is not
used while printing
text.
When OCR
applies, hidden
data will lose.
Word
Shifting
Since altering the
space among words
to complete a line is
relatively frequent,
this identifies lesser.
If someone knows
the design of the
algorithm, it could
be easy to crack.
Abbreviation
This method
appears to be typical
because it is a type
of abbreviation.
Limited for small
data.
Synonym
Method
One of the best
approaches because
it uses various types
of phrases that
effectively hide data
Takes a lot of time
to change one
word to another.
Word
Spelling
An effective way
for hiding data not
only for electronic
documents but also
in the printed text
Less secure.
2) Audio
Audio Steganography is known as when an audio stream
is used as the hide data [3]. Digital audio types including wav,
mp3 are used in this method. Using audio steganography, the
audio signals may be transformed into a form that the
computer can understand in binary format in many ways. [4].
There are several techniques,
LSB Coding - The optimal data transfer rate with LSB
coding is 1kpbs per 1kHZ. The 2 LSB bits of the source are
replaced with two message bits in certain LSB coding
methods [5]. This improves the quantity of data that can be
contained but will increase the level of distortion that is
produced in the audio stream.

Phase Coding - The initial audio part is replaced with a
new phase that holds the secret in this method. Rather than
dividing a signal into individual bits, parity coding separates
it into data segments and encodes every bit of the hidden code
in the parity bit of each data sample sector [6]. The process
modifies the LSB data in the section when the parity bit of a
chosen area and the secret bit that is going to be encoded are
not matched.
Spread Spectrum (SS) - This is a method for encoding any
source of data by distributing the encoded content throughout
the frequency spectrum [6]. SS enables signal receiving even
when there is an interruption on frequencies.
3) Video
Video steganography embeds messages into covering
contents. Video data, in comparison to other formats, is more
feasible to use for data hiding using video steganography. This
method is more efficient because the sensitivity of visual skills
to little differences in form of video in humans is less, hence
video steganography is more effective. Therefore, this method
is used in law enforcement, copyright infringement, access
control, healthcare and more [7]. Because of the larger size,
visual content and the productivity of strong transmission, the
video medium is more qualified than others [7]. , H.264, Mp4,
MPEG, AVI formats are using in Video Steganography [6].
There are three sections:
Intra-embedding - Intra-embedding is a method that
combines video coding embedding with syntactic components
including motion estimation, Direct Cosine Transformation
multipliers (DCT) and intra-prediction and the sender
inserting a secretive text into the video [7].
Diagram - [7]
Pre-embedding - The sender encodes the secret text into
the video before compressing it, Then the receiver decodes
it and recovers the secret text [7]. In pre-embedded video
steganography, the video sequence is generally considered a
sequence of frames. Spatial and transform domain methods
are used for pre-embedding video steganography [7].
Figure 1 Pre-embedding video steganography [7]
Post-embedding - Sender embeds the secret text directly
into the compressed binary string, and the receiver retrieves
the secret text directly from the acquired embedded
compressed video stream using the post-embedding video
steganography method after getting the data [7].
Diagram [7]
Method
Advantages
Disadvantages
Intra-
embedding
•It's simple to assign
the secret message to
the video using intra-
embedding.
•increased anti-
attack ability and
improved subjective
visual quality
•depends on a
certain video codec,
therefore the video
steganography
algorithm's
application scope is
restricted to that
codec.
Post-
embedding
•It is not necessary to
go through the entire
decoding and re-
encoding procedure.
•The computational
difficulty is relatively
low.
•It will not affect the
current video
compression codec's
regular operation.
•The volume of data
contained in the
video is likewise
limited due to
compressed bit rate
limitations.
•The format
converting
operation's stability
is insufficient.
Pre-embedding
•It may utilize several
message hiding tactics
dependent on the
pictures.
•The pre-embedding
approach is unique to a
particular video
coding process and
will not be affected by
the use of existing
standard codecs.
•It takes a long time
and is less
productive.
•The secret message
will inevitably
suffer some loss
during the video
codec, which is
extremely
detrimental to the
extraction and
identification of the
secret message.
4) Image
A pixel is the smallest part of an image, and it consists with
three 8-bit combinations representing Red, Green and Blue.
In image steganography, the bits of the message are used to
replace the least significant bit of the RGB values of the
pixels to hide the message in it. For instance, 3 pixels are
shown below. When hiding the letter V, (ASCII value is 86
which is 01010110) the output is as follows [8].

Since small bit values in pixels are being altered, the
difference is not visible to the human eye. The original image
is called the cover image and after embedding the message it’s
called the stego image. The method is chosen by the
encryption algorithm so both sender and receiver should use
the same algorithm and the key [9].
Tools: Image Steganography, Steghide, Crypture,
SteganographX Plus, rSteg, SSuite Picsel, Our Secret,
Camouflage, OpenStego, SteganPEG, Hide’N’Send [10].
B. Characteristic of data hiding technique
1) Embedding capacity or data payload
The amount of data that can be hidden depends on the size of
the cover media. When the capacity of cover media is high,
the rate of disclosure of hidden messages is low [3].
Data hiding capacity define the capacity of data that is hidden
relative to the amount of the cover object. a major size of data
capacity allows the use of a smaller cover object for data to
adjust the size and reduce the bandwidth [3].
2) Security
When compared to random guessing in a steganalysis system,
having a lower probability estimation of the secret message
is safer. However, the data-hiding technique [3]. In
steganography, may be referred to as unsafe.
3) Embedding efficiency
A Steganography system's embedding effectiveness
determines the possibility of an error [3].
4) Perceptual transparency
The message buried in the cover media causes the sound
distortion of the cover media [3]. During the hiding process,
the perceived quality of the cover item must be kept. When
compared beside each other, the new stego-object should be
so similar to the preceding that it is hard to tell it apart, and
the distinctiveness must be maintained [3].
5) Robustness
After entering the data that must keep intact if the stego object
enters into some transformation [3]. That transformation can
happen in addition to noise in transmission and signal
manipulation.
6) False alarm rate
Possibility of a steganalysis program reporting the existence
of a hidden text when none exists [3].
7) Computation complexity
Expenses for embedding and extracting messages.
C. Incidents where steganography was used:
Al Qaeda leader Osama bin Laden has used popular
websites to communicate by publishing photographs that
contain encrypted messages regarding their terrorist plans
against United States [11]. Some printers use a tracking detail
called machine identification code (MIC) to determine the
source by printing a pattern of yellow dots on each page [12].
Operation Shady RAT in 2011 was a malware that hijacked
data through HTML and JPEG files [13].
III. CONCLUSION
In steganography, there are many ways to hide data in cover
media. Among those, the video medium is better than others
because the data hiding capability is high on videos. It is
required to have the main characteristics in steganography to
do a successful steganography process.
IV. REFERENCES
[1]
R. O. G. a. A. J. Q. Din, "Analytical Review on
Graphical Formats Used in Image Steganographic
Compression," 2018.
[2]
A. J. a. Y. S. Qassim, "Information Security with Image
through Reversible Room by using Advanced
Encryption Standard and Least Significant Bit
Algorithm," International Journal of Advances in
Computer Science and Technology, 2015.
[3]
N. K. S., K. R. G.N. and .. S.A.K, "A review on
steganography through multimedia," 2016.
[4]
K. Mahendra, Steganography and steganalysis of joint
picture expert group (JPEG) images, ProQuest LLC,
2011.
[5]
A. P. S. K.P Adhiya, "Hiding Text in Audio Using LSB
Based Steganography," 2011.
[6]
R. D. M. M. and A. J. Q. , "Review on Steganography
Methods in Multi-Media Domain," Academia, p. 36,
2019.
[7]
Y. L. S. L. Y. W. H. Z. and S. L. , "Video
steganography: A review," Neurocomputing.
[8]
G. L. Team, "Image Steganography Explained | What is
Image Steganography?," 2020. [Online]. Available:
https://www.mygreatlearning.com/blog/image-
steganography-explained/. [Accessed 28 09 2021].
[9]
AnuIyer, "Image Steganography in Cryptography," 16
07 2021.
[10
]
P. Shankadara, "Best tools to perform steganography,"
18 07 2020. [Online]. Available:
https://resources.infosecinstitute.com/topic/steganogra
phy-and-tools-to-perform-steganography/. [Accessed
28 09 2021].
[11
]
S. Vegh, "Hacktivists or Cyberterrorists? The Changing
Media Discourse on Hacking," 2002.
[12
]
Unknown, "Machine Identification Code," 13 09 2021.
[Online]. Available:
https://en.wikipedia.org/wiki/Machine_Identification_
Code. [Accessed 28 09 2021].
[13
]
W. Worrall, "https://hacked.com/the-biggest-hack-in-
history-operation-shady-rat/," 15 03 2021. [Online].
Available: https://hacked.com/the-biggest-hack-in-
history-operation-shady-rat/. [Accessed 28 09 2021].
R
G
B
BEFORE
Pixel 1
01001110
11100101
00010111
Pixel 2
10101100
00110110
11011000
Pixel 3
00000000
11110011
11111001
→
→
→
AFTER
R
G
B
Pixel 1
01001110
11100101
00010110
Pixel 2
10101101
00110110
11011001
Pixel 3
00000001
11110010
11111001