1.1
Background to the Study
The advent of personal Computers and Internet facilities has made digital communication,
processing and distribution of information easy, economical and available globally all day long.
Several applications have been developed to ensure information processing reliable, efficient, fast
and secure. In the Information Technology Industry, there has been a series of bridge in the
information security of individuals and companies which has led to the fall of many companies
and industries. As a result of this bridge in information security, various means has been tried to
curb this criminal act leading to many research theories propounded.
Amidst these various theories propounded, the most advanced theory developed was the Cipher-
Stream technique, which uses a set of undefined keys generated randomly by a key generator and
it has been effectively implemented in all language to ensure Text files were kept secure. The
Cipher-Stream Technique seems to be an effective technique but as years will pass, the need for
information to be stored in images (Simon,2001). The Cipher-Stream Technique seems to be
ineffective as a random generator could be used to break and defile the technique to extract the
Information. Various theories have emerged in which the Image Steganography stands to excel
using a combination of Cipher-Steam Techniques and embedding algorithms, but the advent of
Steganography was not all that was needed because it could also be infiltrated and defile. To enable
information processing secure and difficult to read for intruders, Cryptography was introduced in
the Babylonia era about 4000 B.C (Thwate, 2013).
As Technology advances, many developed countries have adopted the use of images in
information processing in systems such as database, biometrics and security system among many
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others. In ensuring the security and validity of information seen via the Internet and every other
communication medium, various applications have been developed using various Cryptography
Algorithms and Techniques to avoid intrusive attack with one notion in mind that no security
system is safe for eternity, it is only safe the day it was developed (Kaur, 2013).
Cryptography is the process of rendering a meaningful piece of data/information difficult,
meaningless and useless unless it is rightly decoded. Cryptography measures have long been used
by militaries and governments to facilitate secret communication. Cryptography as it stands to
useful for civilian activities and also in protecting data in transit, for example data being transferred
via networks (for example, the Internet, e-commerce), mobile telephones, wireless microphones,
wireless intercom systems, Bluetooth devices and bank automatic teller machines. There have been
numerous reports of data in transit being intercepted in recent years. Encrypting data in transit also
helps to secure it as it is often difficult to physically secure all access to networks. When a message
is decrypted, it is returned to its original readable form. Cryptography/Encryption can provide
strong security for data to give sensitive data the highest level of security (Sharma et al, 2012).
The goal of cryptography is to make data unintelligible to unauthorized readers and extremely
difficult to decipher when attacked hereby affirming the given definition of encryption given above
and Kwang (1967) states that “Cryptography as a process of encoding/enciphering so that its
meaning is not obvious.” According to Kwang (1967) he regarded Cryptography as the
Grandfather of Encoding and Enciphering (Sharma et al, 2012).
Digital Image Cryptography systems differs from the plain text cryptography system such the
image size is often larger/bigger than the text size, any tiny change in the pixel of an image doesn’t
necessarily affect the image unlike the plain text in which any distortion, the whole message is
altered and unrecoverable unless via the use of Advanced Data Recovery Algorithms; there is a
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high level of data redundancy which is found otherwise in plaintext; there is a strong correlation
among adjacent pixels (Sharma et al, 2012).
The scope of the project is to ensure3-Dimensional (3D) images are encrypted, render them
unreadable for the intruders and decrypt the message encrypted message through the use of
Discrete Cosine Transformation technique
Due to the scope of this study, the focus of this project shall be on the Image Encryption and it
will be necessary to understand that the Discrete Cosine Transformation Technique deals with
images as numerical values with a distinctive set of integer values representing the image pixels
in a matrix form of 8 blocks (i.e. 8×8 matrix).
1.2
Statement of the Problem
The inadequacy of the existing Encryption and Decryption System to produce encrypted and
decrypted data with little or no loss of data quality hereby causing insecurity, incorrect delivery of
data, poor data quality among many others. To improve the existing system, there is a need for an
adequate and a secure system with the capacity to distort the image and re-align the set of images
via a mathematical formula to enable decryption move in a reverse array.
1.3
Motivation
Discrete Cosine Transformation Technique stands to be one of the most effective and efficient
cryptographic technique for image cryptography. However, it has been implemented only in the
2Dimensional images (black and white). The desire to implement it on 3D images is the
motivation for this project work.
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1.4
Project Aim and Objectives
The aim of the research is to carry out image encryption using 2-D and 3-D images. The objectives
are as follows:
(i) Design an image encryption system using discrete cosine transformation technique
(ii) Implement the digital image encryption design in (i) above.
1.5
Project Report Structure
This report consists of five (5) chapters, each descriptively explaining its designated details.
Chapter one consists of the introduction which in concise details explains the content, approaches
and methodology to be employed in the project work. It provides the background knowledge of
the project, documenting the foundation of the project work. The other arms of the chapter contain
statement of the problem, the project motivation, its broad aim and several objectives and also this
project report structure.
Chapter two is the literature review; it gives an expository knowledge of the research done into
relevant problem domain, appropriate methodologies, proposed solutions and the appropriate
technologies that support them. It also documents development of existing systems in the research
area or other research area that have tackled similar problems are also documented. It justifies how
the overview of related literature has helped the project in view develop or choose its techniques
or methodologies.
Chapter three entails the Methodology; it shows the methods, techniques, data collection approach,
tools and materials used in achieving the project. It also highlights the requirements specification
section which in expanse gives birth to the functional and non-functional requirements gathering
process. The analysis phase which describes business process model or other high-level conceptual
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view of the required system is also a part of the chapter. Design section describes the system
architecture and displays relevant design diagrams which include interesting features of the project
design.
Chapter four enumerates Implementation, Result and Discussion; this section of the project
documentation presents the implementation related issues such as the approach, materials,
platform, languages, tools used and project status as at time of submission. The details of system
testing and performance evaluation are documented here. This chapter explains with details the
testing, project management and schedule. It highlights other subsections which contain
information such as risk management (identification, analysis and mitigation plan), quality
management and social, legal, ethical and professional considerations made in completing the
project.
Chapter five summarizes and concludes the project report; showing its contribution to knowledge,
limitations and envisaged future works. This chapter also critically appraises the project work
demonstrating the knowledge and expertise gained from it. Bibliography, references and appendix
concludes the project report.