Instant Messaging has become an important means of communication between people around the globe, providing an alternative to telephone and email conversations. The number of users using Instant Messenger products has been increasing over recent years. Messenger services provide a perfect environment for private and personal chat. People of all ages log into messenger service or chat rooms to spend time chatting with known and unknown persons. The aim of the project is to develop a client server java chat application with security in mind. The use of Encryption and decryption algorithm forms part of this project where by messages exchanged between client and server are encrypted and decrypted with a symmetric private key. The project overview that shows the structure of the project design is depicted in introduction part of this document. This paper also contains the literature review which has been categorized into historical and theoretical review.  Most existing product such as AOL, MSN, yahoo messenger provide their customers with a free instant messaging but over the past few years, their security has not been trusted. The theory or speculations that makes up the proposed system is elaborated most in the theoretical review of this paper

1.0 Introduction

Every day, people in the office and at school are instant messaging to communicate with their peers. Use of the technology, which allows for synchronous, virtual communication, has been steadily rising over the past five years. (Madden 2003) Instant Messaging, also known as online chat, represents the most impressive online revolution since the advent of email.

In this 21st century, there has been much achievement in computing and telecommunication. The ubiquity of information has lead to the widespread of various web 2.0 technologies such as Skype, telepresence; instant chat messaging etc, that enables effective facilitation and communication of information. 

Instant messaging is a real-time communication medium that has grown increasingly popular for both social and professional use. In the business world, messaging can be used advantageously in scenarios where phone use is not possible or appropriate, for example in communicating with geographical distributed teams, or for technical discussions in which the sending of URLs or operating system commands can be instantaneous. However, a company whose employees uses messaging as a work-based discussion tool has coarse to be more concerned about security issues than a casual user who uses the software to keep in touch with friends.

Instant messaging has become an important means of communication between people around the globe, providing an alternative to telephone and email conversations. The number of users using instant messenger products has been increased over the recent years. Messenger services provide a perfect environment for private and personal chat of which people of all ages log into messenger service or chat rooms to spend time chatting with known and unknown persons. Instant messaging means sending the required message quickly from one workstation to the other in a less period of time which is purposefully useful for business persons and other large companies too. The total number of instant messenger in this I.T world follows the client server architecture whereby various clients are made to communicate on a network upon connection establishment with the server.

Instant messaging is a type of chat application that offers real time text transmission over a network or the internet. In recent years, instant messaging systems have gained more and more

Popularity as a new means of communication over a network. Instant messengers such as MSN, yahoo messenger, etc are online based that allow their users to exchange text messages but, unlike email, the sender and the recipient of a message are online at the same time. In this respect communicating via an instant messaging system is more similar to using telephone. Even though, most of these existing instant messengers can be reliable in message transmission from one point to the other, they have shown to have severe security problems with respect to user privacy, message authenticity and eavesdropping.

1.1. Statement of the problem

One major disadvantage of most instant chat application is their prone to security attacks. Forinstane, yahoo messenger is venerable to security attacks when instant messages are sent between a source and a destination machine. The reason is the fact that, messages which are sent over the network is in a plaintext format with no encryption and decryption protection, thereby enabling intruders with no privileges to gain authentication sequence  and alter the message content and make modifications to the message stream, learn the traffic pattern and course denial of service.  

1.2. Project overview and organizational profile

This project is intended to develop an instant chat application known as Secured Java chat messenger (SJCM). SJCM is an instant chat application that provides an intuitive and reliable way of exchanging instant messages over a network using two or more computers.  However SJCM (Secured Java chat messenger) provides an assurance of network security where plaintext are transformed into cipher text (Unintelligible message), thereby making it difficult for a cryptanalysisit or intruder attempts to alter message content and make modifications to the original plaintext. SJCM consists of two separate models. The server chat application module (independent) and the client chat application module (dependent). The server chat application module provides a graphical user interface with settings and options which enables an effective and secured exchange of instant messages between two or more communicating entities. Similarly, the client chat application module also contains a graphical user interface and provides a reliable and secured communication. Secured java chat messenger would be built upon the ideology of the client server architecture model. However, these two modules (server and client chat module) can communicates with each other on a network upon a connection establishment which would be dependent on the host computer’s port numbers and IP addresses. Each model would contain an encryption and decryption scheme using the Advanced encryption standard (AES) algorithm, that would require a user on the network to encrypt the plaintext into a cipher text with a private symmetric key before making the transmission on the network and decrypt the cipher text into a plaintext with the same private symmetric key at the receiving end of the communication. A symmetric private key is a unique pass code that is used to secure an encrypted plaintext at the transmission end of the communication and used to decrypt the cipher text into a plaintext at the receiving end of the communication. Below is an illustration that depicts the overview of this project.

 

Figure 1.2 Project Overview and organizational profile

1.3. Existing System

Free instant messaging (IM) programs such as those provided by the American online, MSN, Outlook express and yahoo have proved popular for leisure use. These companies provide a free messaging service by integrating their software as part of a much wider spectrum of web services to increase customer loyalty. Once downloaded to the client’s computer, the user can log in and engage in real time conversations with a personal contact. Later versions of these IMs provide highly quality interface and functionality to transfer files or hold a video conference. 

Most of the instant messengers require users of their IM to open a user account at their particular domain, for example an MSN user would login under their hotmail address before initializing the chat application. Other instant messengers such as outlook express also support offline instant chat messaging. However, in the absence of the internet, two or more entities can still exchange instant messages provided they are visible in a network domain, such as intranet, LAN etc. In spite of the existing systems ease of use, many companies do not use these free IM for communication over the internet and a network as well, as their security was not fully trusted; a work based discussion conducted by two employees is thought to run the risk of having confidential information being intercepted outside of the local network.

1.4. Project Objectives

However , the purpose of this project is to develop a java chat application where by instant messages are encrypted with a private key at the transmission end, and decrypted with the same private key at the receiving end on the network using the Advanced encryption standard algorithm (AES standard) . The objective of this project is as follows;

1. To develop a client server java chat application that will enable instant messaging between host computers on a network

2. To provide security of information (messages) by performing an encryption and decryption scheme due to which the messages together with the private key is transferred in a cipher text format over the network rather than plain text so as to disallow intruder’s attempt.

3. To provide authentication of the message so as to know whether the message has been sent by the genuine or intended user

4. To provide Data integrity of the message so as to confirm whether the message is received exactly as it was sent.

1.5. Justification

In this project, I therefore propose to design a chat application that will purposely enable host computers on a network to exchange messages instantly. By the design and implementation, the application will serve as a source of security on a network since the application will be made up of an encryption and decryption protection of each model, thereby transmitting the cipher text version of the original plaintext on the network. This would be reliable and efficient in managing information to database server center which will eventually improve the performance. No centralized database to access natural and technical event at real times.

1.6. Risks

Below are the risks that may be associated with the use of Secured Java Chat Messenger (SJCM);

 Hardware of both server and client workstations can be wiped out and there can be impromptu shutdown whiles the application is still running

 There may be occurrences of exception java run time errors that will disable the application from working if there is no java run time environment installed on the host computer.

 There can be undesirable system behavior if for instance an invalid port number is inputted in one of the application modules.

 Monitors, such as cathode ray tube emit powerful radio-active waves, a form of non-ionizing electromagnetic radiation which can be absorbed by the tissues of the human eye. 

1.7. Scope of study

Secured Java chat messenger (SJCM) is a connection oriented service which requires the two applications (server and client chat module) to exchange port numbers and IP addresses, therefore, the scope of study is to implement the objectives of this project.