School of Computing: Steganography and Steganalysis Techniques Report

This report provides a comprehensive overview of steganography and steganalysis, crucial techniques in digital crime investigation. It begins with an introduction to these concepts, defining steganography as the art of secret communication and steganalysis as the detection of hidden messages within digital media. The main body delves into the classification of different steganographic and steganalytic techniques. The report covers linguistic steganography, which utilizes natural languages, and technical steganography, which employs scientific methods for concealing secret communications in images, audio, and video. It explores techniques like LSB insertion, phase coding, and others. The report concludes by emphasizing the historical and technological evolution of these methods, highlighting their importance in protecting secret and private information in the digital age. The report is well-structured, providing a detailed account of the techniques and their applications.

Steganography and Steganalytical
Techniques

Table of Contents
INTRODUCTION...........................................................................................................................1
MAIN BODY...................................................................................................................................1
Overview of Steganography and Steganalysis............................................................................1
Classification of different techniques used within Steganography and Steganalysis..................2
CONCLUSION................................................................................................................................3
REFERENCES................................................................................................................................4

INTRODUCTION
Steganography refers to an art of digital crime investigation techniques in terms of secret
communication, while steganalysis includes a procedure of detecting the hidden messages which
are embedded within digital media (Karampidis, Kavallieratou and Papadourakis, 2018). From
the media and law enforcement, both these concepts have expected to a great deal of attention. In
this paper, major focus is given on classification of both techniques from other investigation
techniques, for providing an account of different approaches which have been proposed for
digitally investigations.
MAIN BODY
Overview of Steganography and Steganalysis
The term steganography is mainly derived from terminologies of Greek words which
provides the data related to secret transmission. This concept hides the message which includes a
collection of graphical images, sound or video files etc. from another messages within a storage
medium (Zhu, Zhao and Guan, 2019). While, Steganalysis includes a procedure of detecting and
identifying the presence of hidden information. The main goal of this technique is to identify the
suspected message and determine whether it contains a payload or not, if encoded then recover
the same as well. In contrast with other techniques like cryptography, it changes the secret
communications from one form to another, due to which message is unreadable, scrambled, as
well as the existence of the same (Zhang and et. al., 2019). Therefore, this encryption of message
often looks meaningless, where caution is required while reusing any key. It is mainly used for
protecting message contents during transmission of information from sender to receiver. While
steganography instead of encryption, hides information usually messages which is carried inside
data. In this regard, quite having similar concepts but yet messages under cryptography are
difficult to understand. In today’s digitalised world, steganography is considered as an important
tool, which can be utilised easily rather than cryptography for large data formats
like .gif, .bmp, .doc, .txt and more. So, it provides security and privacy to open systems like
internet more efficiently.
Steganographic techniques are used from various centuries where, the first known
application in the ancient Greek times includes tattoed messages on shaved heads of messengers,
then let them for growing hair on the same, in order to remain messages unseen (Rehman and et.
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al., 2019). After then with improving technologies in 20th century, the most widely technique is
used is invisible inks like wax table, written text by fluids like milk, vinegar, fruit juices and
more, has been developed for protecting messages from others. Thus, it has been analysed that
using steganography technique, a messenger can send messages privately by hiding the
knowledge of existence of any kind of communication from others. There are various developed
and underdeveloped countries where it communicating freely is not possible sometimes. In this
regard, Steganography has made it for them to send news and information easily, without being
feared and censored regarding with interceptions and being traced of their messages (Yahya,
2019). Apart from sending messages, this technology can also use for storing information such as
military secrets, private banking and more on different location like in a cover source.
Classification of different techniques used within Steganography and Steganalysis
Digital steganography hides information generally into covert channels, for concealing the
same and prevent any kind detection (Yahya, 2019). This type of Covert channel includes a
genre of information regarding with security research, in the industry, academia and government
domains. The data which is hided in steganography is mostly intended in such a manner that only
receiver will know the existence of hidden information. Therefore, it is quite different from
cryptography that mainly emphasise for encoding the messages via scrambling, where to read
information, a specific key is used. Another main technique includes digital watermarking,
which is concerned with issues that are related to intellectual property rights like copyright
(Rehman and et. al., 2019). In this regard a watermark generally contains the information which
is pertaining to receiver and sender. In context with well-known steganographic methods that
include covert channel, spread-spectrum communication, invisible ink and microdot to protect
information. For hiding information, this digital tool i.e. Steganography includes two main
methods – Linguistic Steganography and Technical Steganography, as explained beneath:
Linguistic Steganography
This technology mainly utilises the natural languages for hiding information and can be
categorised into open codes and semagrams. Here, one of the major transformation of data
includes synonyms substitution, to encode the hidden bits of information (Zhang and et. al.,
2019). Under this process, secret information or cover words is replaced by their synonyms,
which is generally known as mechanism of embedding the data from one form to another. For
ensuring the lexical substitutions of words in the cover text whether imperceptible or not,
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Steganography system utilise the Google n-gram corpus. This would help in checking the
applicability of desired word’s synonym in cover context (Zhu, Zhao and Guan, 2019). Along
with this, respective system also assigns codes for all acceptable substitutes by using a novel
vertex coding method. Under this method, hidden words are mostly represented as vertices
within a graph, where synonyms of each are linked by edges, and in addition to this, the bits are
also assigned along with the vertex which represent specific code of a particular word.
Technical Steganography
It refers to a scientific method for concealing the secret communications like invisible
ink, shaved heads and microdot. Hereby, chemical of physical means are utilised for hiding
information and therefore, categorised in terms of Image, audio and video. Here, in image
steganography includes a collection of various numbers which contains intensities and different
colours of light on several regions of images to a computer. Image pixels in this process are
represented by rectangular matrix (Karampidis, Kavallieratou and Papadourakis, 2018). Under
this process, to hide or embed the information, a number of methods like LSB insertion, Masking
& Filtering, Algorithms & Transformation etc. can be used. In context with audio, secret
information is embedded in digital sound within an audio Steganography system, via marginally
changes the binary sequence of particular audio file. This method as comparison with other
technical steganography, considered as most difficult one, where to conceal the secret messages
in successful manner, a number of methods are required. It includes Low-bit coding, Parity
coding, Phase coding and so on. Other than this, Video Steganography combines both audio and
image procedures for hiding secret information. The most beneficial part of this method is to
embed the large amount of information inside of sound and images more easily. Thus, it has been
analysed that steganography can be defined as an encryption technique which can be used with
cryptography in terms of extra-secure method for protecting secret and private information.
CONCLUSION
It has been summarised from entire report on Steganography and Steganalysis that these
methods are being used from many centuries, to hide the secret information from others. The
only difference in today’s 21st century and the past history is the changes of technology. With
advancement of technologies, it becomes possible to hide secret any type of data like audio,
video, image and text, from others more easily and in authenticate manner.
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REFERENCES
Books and Journals
Rehman, A. and et. al., 2019. Data hiding technique in steganography for information security
using number theory. Journal of Information Science. 45(6). pp.767-778.
Yahya, A., 2019. Steganography Techniques for Digital Images. Springer.
Zhang, J. and et. al., 2019. Binary image steganography based on joint distortion
measurement. Journal of Visual Communication and Image Representation. 58. pp.600-
605.
Zhu, J., Zhao, X. and Guan, Q., 2019. Detecting and Distinguishing Adaptive and Non-Adaptive
Steganography by Image Segmentation. International Journal of Digital Crime and
Forensics (IJDCF). 11(1). pp.62-77.
Karampidis, K., Kavallieratou, E. and Papadourakis, G., 2018. A review of image steganalysis
techniques for digital forensics. Journal of information security and applications. 40.
pp.217-235.
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