Data encryption has been widely applied in many data processing areas. Various encryption algorithms have been developed for processing text documents, images, video, etc. If we are able to collaborate the advantages of the different existing encryption methods, then a new hybrid encryption method can be developed which offers better security and protection. So, in order to accomplish the Hybrid encryption technique, data encryption techniques using Fibonacci series, XOR logic, PN sequence are studied, analyzed and their performance is compared in this paper. The message is divided into three parts and these three different techniques are applied to these parts and the performance is again analyzed. The application of these three different methods to different parts of the same message along with two keys, namely, segmenting key and encrypting key to provide further authentication and validation is the basis of our paper.

CHAPTER ONE

INTRODUCTION

1.1  Background of the Study

Nowadays advances in Information Communication and Technology are now bringing innovation in different domains, there is huge amount of data being collected, stored and exchanged. Everywhere across the world organizations can connect and share information no matter the location. Then infrastructure, data and application security become more important (Prakash & Saeed, 2014).

The data security system means protecting data from destructive forces and from the unwanted actions of unauthorized users. Communication and transmission of data over networks has increased exponentially since the last few years. The data security hierarchy involves challenges and issues which encryption algorithms intend to reduce. To achieve the goal of securing data, the ability of specific type of cryptograph algorithm (symmetric and asymmetric) need to be considered. Cryptography is the process of converting plain text into encrypted text and vice versa. In a distrusted medium cryptography becomes essential part of securing communication (Rajan & Geeta, 2013).

One of the methods of cryptography is encryption of data, prepared to be transferred in encrypted way and decrypted when the data is to be used (Greg 2006). Encryption is the process of transforming plaintext data into cipher text to conceal its meaning thereby preventing any unauthorized recipient from retrieving the original data (Naser et al 2013).  This is usually done with the use of an encryption key, which specifies how the message is to be encoded. Modern encryption algorithms play a vital role in the security assurance as they can provide not only confidentiality but also authentication, integrity and non repudiation (Margaret, 2014). Any third party, who wants to interfere the communication by accessing or changing the data, is called an intruder. Intruder can destroy confidentiality by intercepting the data, violate the integrity by changing the content of the data and finally impersonate the sender of the data to affect also authentication (Shubhra & Datta, 2013).

1.2  Statement of the Problem

For data security using hybrid encryption technique, AES and RSA are among the most used encryption algorithms from symmetric and asymmetric respectively. However each of them has weaknesses which render them vulnerable to intruders. AES has a challenge to achieve the key distribution because it uses third party channels to deliver the secret key. There is no control mechanisms in place for the third party which communicate the secret key. The probability that should be an intruder listening to discover the secret key is high. The symmetric encryption algorithms are more secured in terms of key size to encrypt huge data.

RSA is asymmetric cryptography tried to fix the issue of sharing keys. The major advantages of asymmetric are use of two different keys and providing digital signatures to achieve authentication of sender. Even if RSA algorithm has the aforementioned advantages its main problem is slowness to compute data. RSA algorithm take longer than AES to encrypt and decrypt huge data.  The intruder has enough space to detect mathematically the key while encrypting data due to low speed of processing time.

The achievement of the cryptography’s functionalities such as integrity, confidentiality and authentication and non-repudiation, by the use of only among above-mentioned algorithms is a challenge. The key distribution and authentication of data source become a major problem for AES because intruder can manage to get secret key. Then decrypt the data which can affect data confidentiality and data integrity. The AES doesn’t provide signature on the data transmitted, to ensure the authentication and non-repudiation. The RSA algorithm is very slow and complex to implement. The slowness of RSA gives an open window to attackers during the process then data encryption then integrity is affected.

1.3 Objectives of Study

The main objective of this study is to construct hybrid technique to extremely enhance the security of data. Its discusses, compares and analyzes the main features of AES and RSA that  leads to construct new hybrid encryption.  This study will also evaluate the enhancement of data security provided by hybrid encryption technique.

1.4 Significance of the Study

The study will contribute in the enhancement of data security and cryptography using hybrid technique between two algorithm AES and RSA. The study will help to know how the security of data in transit can be enhanced.

1.5 Scope of the study

This research is going to analyze AES and RSA encryption algorithm then construct a new hybrid encryption technique. This study is based on organizations which have the option of storing and transmitting data. Theoretically the study will cover the attributes of identification, analysis, and construction of hybrid technique to secure data.