In this era of global communication where online communication through the use of computer network and telecommunication system has dominated the means of communication between people. The goal of privacy is very paramount. The numbers of people being connected to the communication system through their mobile phone, computer or any other e-communication tools are increasing day-by-day. Hence there is need to secure the communication networks from adversaries (third parties) between the sender and receivers. There are many aspects to security approach in data communication environment. One essential aspect for secure communications is that of cryptography, which the focus of this research is. We have developed stand-alone application software that implements cryptography using Caesar algorithms. This program can be implemented with chatting software or E-mail software to encrypt data. The algorithm was coded with Java programming language.

1. International Journal of Engineering and Advanced Technology (IJEAT)
ISSN: 2249 – 8958, Volume-4, Issue-4,
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Published By:
Blue Eyes Intelligence Engineering
& Sciences Publication Pvt. Ltd.
Abstract— In this era of global communication where online
communication through the use of computer network and
telecommunication system has dominated the means of
communication between people. The goal of privacy is very
paramount. The numbers of people being connected to the
communication system through their mobile phone, computer or
any other e-communication tools are increasing day-by-day.
Hence there is need to secure the communication networks from
adversaries (third parties) between the sender and receivers.
There are many aspects to security approach in data
communication environment. One essential aspect for secure
communications is that of cryptography, which the focus of this
research is. We have developed stand-alone application software
that implements cryptography using Caesar algorithms. This
program can be implemented with chatting software or E-mail
software to encrypt data. The algorithm was coded with Java
programming language.
Index Terms— Caesar Cipher, Cryptography, Java
programming language, Computer network
I. INTRODUCTION
The goal of privacy is achieved if a message is only
received by the intended recipients. This goal is normally
accomplished using encryption algorithms. Encryption
algorithms convert the original message, called the plaintext,
into an encrypted form called the ciphertext that must be
decrypted back into the plaintext by the recipient in order for
it to be meaningful.
Most ciphers use a piece of information called a key for
encryption and decryption, and ciphers that use the same key
for both processes (sender and recipient) are called
symmetric keyciphers, as opposed to asymmetric key ciphers,
in which the keys are different on both sides of the message
transmission channel [1].
Cryptographyis the science of writing in secret code and is
an ancient art; the first documented use of cryptography in
writing dates back to circa 1900 B.C. when an Egyptian
scribe used non-standard hieroglyphs in an inscription. Some
experts argue that cryptography appeared spontaneously
sometime after writing was invented, with applications
ranging from diplomatic missives to war-time battle plans. It
is no surprise, then, that new forms of cryptography came
soon after the widespread development of computer
communications [2].
In cryptography, a Caesar cipher is one of the simplest and
most widely known encryption techniques. It is a type of
substitution cipher in which each letter in the plaintext is
replaced by a letter some fixed number of positions down the
alphabet. For example, with a shift of 3, A would be replaced
by D, B would become E, and so on. The method is named
after Julius Caesar, who used it in his private correspondence
[3]. The focus of this paper is to design and implement a
caser cipher application system that can protect data from
theft or alteration, and also be used for user authentication
when communicating over any untrusted medium, which
includes just about any network, particularly the Internet.
In Caesar Cipher the transformation can be represented by
aligning two alphabets; the cipher alphabet is the plain
alphabet rotated left or right by some number of positions.
For instance, here is a Caesar cipher using a left rotation of
three places (the shift parameter, here 3, is used as the key):
Plain: ABCDEFGHIJKLMNOPQRSTUVWXYZ Cipher:
DEFGHIJKLMNOPQRSTUVWXYZABC. When
encrypting, a person looks up each letter of the message in
the "plain" line and writes down the corresponding letter in
the "cipher" line. Deciphering is done in reverse [4]. The
diagram below illustrates a typical Caesar Cipher. The
Caesar Cipher is an encoding method that works like this;
this example is for a shift amount of 13, which is a ROT-13.
if (character is in alphabet)
{
if(character is in bottom half of alphabet [A-M|a-m] )
character = character + 13;
else /* character is in top half [N-Z|n-z] */
character = character – 13;
}
print(character);
In a Caesar cipher, each letter is replaced by a letter further
along in the alphabet. You can think of it as shifting the
alphabet to the left. The key of a Caesar cipher is the number
of places the alphabet is shifted. Here is a Caesar cipher with
key 3:
A.Objectives of This Research Work
The objectives of this research work are to:
 To achieve the goal of privacy in data communication
and telecommunication system i.e. a message is
only received and decoded by the intended
recipients.
 To provide confidentiality, authenticity, integrity,
and non-repudiation of the information transmitted
through the online
Data Security on Computer Network and
Telecommunication System Using Caesar Cipher
Cryptography Algorithm: AJava Implementation
Akinyele A. Okedola, Yekini N. Asafe

2. Data Security on Computer Network and Telecommunication System Using Caesar Cipher Cryptography Algorithm:
A Java Implementation
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Published By:
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communication network.
 To develop a cryptographic algorithm that is an
improvement on the existing system
B.Scope of Study
This research work focuses on design and implementation
of cryptosystems for preventing third parties from assessing
data/information (message) between sender and receiver on
online communication using caesar algorithm with java
programming language.
II.LITERATURE REVIEW
A.Cryptograph Concept and Data Communication
In data and telecommunications, cryptography is
necessary when communicating over any untrusted
medium, which includes just about any network,
particularly the Internet. Within the context of any
application-to-application communication, there are some
specific security requirements, including:
 Authentication: The process of proving one's identity.
(The primary forms of host-to-host authentication
on the Internet today are name-based or
address-based, both of which are notoriously weak.)
 Privacy/confidentiality: Ensuring that no one can
read the message except the intended receiver.
 Integrity: Assuring the receiver that the received
message has not been altered in any way from the
original.
 Non-repudiation: A mechanism to prove that the
sender really sent this message.
Cryptography, then, not only protects data from theft or
alteration, but can also be used for user authentication.
There are, in general, three types of cryptographic schemes
typically used to accomplish these goals: secret key (or
symmetric) cryptography, public-key (or asymmetric)
cryptography, and hash functions, each of which is
described below. In all cases, the initial unencrypted data is
referred to as plaintext. It is encrypted into Cipher text,
which will in turn (usually) be decrypted into usable
plaintext [4].
B.History and usage Caesar Cipher
The Caesar cipher is named after Julius Caesar, who,
according to Suetonius, used it with a shift of three to protect
messages of military significance. While Caesar's was the
first recorded use of this scheme, other substitution ciphers
are known to have been used earlier.
If he had anything confidential to say, he wrote it in
cipher, that is, by so changing the order of the letters of the
alphabet, that not a word could be made out. If anyone wishes
to decipher these, and get at their meaning, he must
substitute the fourth letter of the alphabet, namely D, for A,
and so with the others.
It is unknown how effective the Caesar cipher was at the
time, but it is likely to have been reasonably secure, not least
because most of Caesar's enemies would have been illiterate
and others would have assumed that the messages were
written in an unknown foreign language.[4] There is no
record at that time of any techniques for the solution of
simple substitution ciphers. The earliest surviving records
date to the 9th century works of Al-Kindi in the Arab world
with the discovery of frequency analysis. [5]
A Caesar cipher with a shift of one is used on the back of the
mezuzah to encrypt the names of God. This may be a
holdover from an earlier time when Jewish people were not
allowed to have mezuzot. The letters of the cryptogram
themselves comprise a religiously significant "divine name"
which Orthodox belief holds keeps the forces of evil in check
[6].
In the 19th century, the personal advertisements section in
newspapers would sometimes be used to exchange messages
encrypted using simple cipher schemes. Kahn (1967)
describes instances of lovers engaging in secret
communications enciphered using the Caesar cipher in The
Times. [7] Even as late as 1915, the Caesar cipher was in use:
the Russian army employed it as a replacement for more
complicated ciphers which had proved to be too difficult for
their troops to master; German and Austrian cryptanalysts
had little difficulty in decrypting their messages.[8]
Caesar ciphers can be found today in children's toys such as
secret decoder rings. A Caesar shift of thirteen is also
performed in the ROT13 algorithm, a simple method of
obfuscating text widely found on Usenet and used to obscure
text (such as joke punchlines and story spoilers), but not
seriously used as a method of encryption. [9]
A construction of 2 rotating disks with a Caesar cipher can be
used to encrypt or decrypt the code.
The Vigenère cipher uses a Caesar cipher with a different
shift at each position in the text; the value of the shift is
defined using a repeating keyword. If the keyword is as long
as the message, chosen random, never becomes known to
anyone else, and is never reused, this is the one-time pad
cipher, proven unbreakable. The conditions are so difficult
they are, in practical effect, never achieved. Keywords
shorter than the message (e.g., "Complete Victory" used by
the Confederacy during the American Civil War), introduce
a cyclic pattern that might be detected with a statistically
advanced version of frequency analysis. [10]
In April 2006, fugitive Mafia boss Bernardo Provenzano was
captured in Sicily partly because some of his messages,
written in a variation of the Caesar cipher, were broken.
Provenzano's cipher used numbers, so that "A" would be
written as "4", "B" as "5", and so on. [11]
In 2011, Rajib Karim was convicted in the United Kingdom
of "terrorism offences" after using the Caesar cipher to
communicate with Bangladeshi Islamic activists discussing
plots to blow up British Airways planes or

3. International Journal of Engineering and Advanced Technology (IJEAT)
ISSN: 2249 – 8958, Volume-4, Issue-4,
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Published By:
Blue Eyes Intelligence Engineering
& Sciences Publication Pvt. Ltd.
disrupt their IT networks. Although the parties had access to
far better encryption techniques (Karim himself used PGP for
data storage on computer disks), they chose to use their own
scheme(implemented in Microsoft Excel), rejecting a more
sophisticated code program called Mujhaddin Secrets
"because 'kaffirs', or non-believers, know about it, so it must
be less secure". [12]
The animated series Gravity Falls uses the Caesar cipher as
one of three different ciphers (the other two being Atbash and
an A1Z26 cipher) during the end credits of the first six
episodes.
C.Mathematical Description of Caeser Cipher
To give a mathematical description of caeser cipher, First we
translate all of our characters to numbers, 'a'=0, 'b'=1, 'c'=2,
... , 'z'=25. We can now represent the caesar cipher
encryption function, e(x), where x is the character we are
encrypting, as:
Where k is the key (the shift) applied to each letter. After
applying this function the result is a number which must then
be translated back into a letter. The decryption function is:
III. DESIGN METHODOLOGY, IMPLEMENTATION AND TESTING
A.Design Methodology
This new system will use the same key for both sender and
receiver for encryption and decryption of data. The design
and flow of program will be based on the principle of
encrypting system architecture in figure I. The program
source code is displayed as shown appendix. This program
will help to achieve the goal of privacy in data
communication and telecommunication system.
Figure 1: Encrypting System Architecture
B.Testing and Implementation
The software application program was tested, and it was
observed that it performs the major objectives of the research.
The output is as in the figure below.

4. Data Security on Computer Network and Telecommunication System Using Caesar Cipher Cryptography Algorithm:
A Java Implementation
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Published By:
Blue Eyes Intelligence Engineering
& Sciences Publication Pvt. Ltd.
Figure 2: Interface Shown Plaintext
Figure 3: Interface Shown Cypher text

5. International Journal of Engineering and Advanced Technology (IJEAT)
ISSN: 2249 – 8958, Volume-4, Issue-4,
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Published By:
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III. CONCLUSION
In this era of global communication through the use of
computer network, telecommunication system and devices,
the need for security of information/data from sender cannot
be over emphasized. Hence there is need for a platform to
prevent unauthorized access to information been sent from
sender to receiver on data communication and
telecommunication system. One of the best methods to
prevent such ugly occurrence of intruder or hijacker to make
use of one data is through the use of Cryptosystem. We have
developed stand-alone application software that implements
cryptography using Caesar algorithms. This program can be
implemented with chatting software or E-mail software
where the data transmitted over a data communication
network.
IV. FURTHER RESEARCH
The system does have a high confidentiality rating in order
to defend against sniffing and man-in-the-middle attacks. It
was observed that the algorithm used was focus on
encrypting only alphabetic data. This means that it cannot
guarantee full security for interception of data within
financial world and mathematics environ. Consequence to
this we proposed a further research in which the Caesar
algorithm will be modified to accommodate all alphanumeric
data and formulae symbol implemented on a computer
network.
REFERENCES
[1] D.E. Comer (2004) Computer Networks and Internets. 4th Edition.
Chapter 40: Network Security Prentice Hall, 2004.
[2] Oludipe O., Yekini N.A., and Adelokun P.A (2011). Data
Communication and Computer Network. Hasfem Publication Nigeria.
[3] Alberto Leon-Garcial and Indra Widjaja. Communication Networks,
Fundmental Concepts and Key Architecture. Second Edition,
McGraw-Hill Publishing Company, New dehlhi 2004
[4] Singh, Simon (2000). The Code Book. Anchor. pp. 14–20. ISBN
0-385-49532-3.
[5] Kahn, David (1967). The Codebreakers. pp. 775–6. ISBN
978-0-684-83130-5).
[6] Leighton, Albert C. (April 1969). "Secret Communication among the
Greeks and Romans". Technology and Culture 10 (2): 139–154.
doi:10.2307/3101474. JSTOR 3101474.
[7] Leyden, John (2006-04-19). "Mafia boss undone by clumsy crypto". The
Register.
http://www.theregister.co.uk/2006/04/19/mafia_don_clueless_crypto/.
Retrieved 2008-06-13.
[8] Luciano, Dennis; Gordon Prichett (January 1987). "Cryptology: From
Caesar Ciphers to Public-Key Cryptosystems". The College Mathematics
Journal 18 (1): 2–17. doi:10.2307/2686311
[9] Pieprzyk, Josef; Thomas Hardjono; Jennifer Seberry (2003).
Fundamentals of Computer Security. Springer. p. 6. ISBN
3-540-43101-2.
[10] Beutelspacher, Albrecht (1994). Cryptology. Mathematical Association
of America. pp. 9–11. ISBN 0-88385-504-6.
[11] Beutelspacher, Albrecht (1994). Cryptology. Mathematical Association
of America. pp. 8–9. ISBN 0-88385-504-6.
[12] Sinkov, Abraham; Paul L. Irwin (1966). Elementary Cryptanalysis: A
Mathematical Approach. Mathematical Association of America. pp.
13–15. ISBN 0-88385-622-0.
[13] Savarese, Chris; Brian Hart (2002-07-15). "The Caesar Cipher".
Retrieved 2008-07-16.
AKINYELE Akinleye Okedola
Obtained B.Sc. Electronics & Computer
Engineering from Lagos State University
and M.Sc. in System Engineering from
University of Lagos. He is a Certified
Wireless Network Administrator
(CWNA), I.T Consultant, Engineer and
a Professional Teacher. He was a head of
Department of Computer Engineering,
Lagos State Polytechnic, and presently
the Head, Record and Statistics in the
Academic Planning Unit of Lagos State
Polytechnic.
Engr. Yekini Nureni Asafe obtained his
academic qualification as follows: M.Sc.
in Computer Science, University of Lagos
Nigeria (UNILAG); B.Sc. in Electronic
and Computer Engineering, Lagos State
University (LASU), and NCE (National
Certificate in Education) in Physics Lagos
State College of Education Ijanikin
(LACOED). He is a Member Nigeria
Computer Society (NCS), International
Association of Engineers (IAENG),
International Association of Computer
Science and Information Technology
(IACSIT), and Member Institute of
Electrical Electronic (MIEEE). He has
co-author, and singular author of several
academic/research publications that has
features in some revered international
journals and conference proceedings both
in Nigeria and in abroad. He has written
about seventeen textbooks in computer
science and engineering