MODIFIED VERTICALLY SCRAMBLED CAESER CIPHER METHOD FOR ENHANCED DATA SECURITY

MSC Project Topics in Computer Science

ABSTRACT 

Cryptography is the art and science of converting readable messages into non-readable form. The two techniques for converting data into non-readable form are transposition technique and substitution technique. Caesar cipher is an example of a substitution method. Although Caesar cipher is the simplest type of cipher, it suffers from the limitation of character repetition which makes it prone to plain text or brute force attack. Many researchers have developed techniques to address this problem by improving on key generation or combining two or more algorithms. Despite these efforts, the problem of character repetition still exists. To overcome this limitation, this work proposed a new data security solution using the modified Caesar cipher that eliminates character repetitions. The proposed system is expanded to include alphabets, numbers and symbols. The proposed method is resistant against brute-force attack with 256 keys. It also employs more confusion and diffusion to make the transmission of messages more secure and robust. The algorithm was evaluated based on frequency of character occurrence, character length, running time and security. The proposed system produced cipher texts with entropy value up to 60% higher and index of coincidence 11% lower than that of Vertically Scrambled Caesar Cipher Method. These enhancements are obtained at the expense of acceptable additional computation overhead (running time) of up to 15% in the worst case.

CHAPTER ONE

INTRODUCTION

This chapter discusses the introductory part of this dissertation, which includes background of the study, research motivation, problem statement, research objectives, and finally the dissertation outline.

1.1 Background to the Study

People live in an information society where they rely on the exchange and processing of information. Evidence of this evolution is the rapid growth of communication networks, and a trend towards complex software applications with strong security requirements. Examples of these are the increasing use of portable devices and wireless networks, communication with friends and colleagues via e-mail and chat, the launch of (interactive) digital television and other media platforms (e.g., iTunes), on-line banking and purchase of goods and services, online gaming, GPS navigation, professional and social networks (e.g., LinkedIn and Facebook) and many more (Wyseur, 2009). In one way or another, these new trends affect daily activities in many ways, at home and in our professional life. On the downside however, people have become increasingly dependent on the information infrastructure that empower information society, and hence potentially vulnerable to attacks on them. In recent years, this has been illustrated by attacks on Internet servers, credit card fraud, hacking of banking applications and on-line games, cell phones and TV set-top boxes, phishing, privacy violation, botnet threats, and so forth (Wyseur, 2009).

In order to support information society for the next years and take advantage of the opportunities that it enables, the need for trustworthy information infrastructure is growing. The trend towards complex software applications with strong security requirements increasingly demands for qualitative protection technologies. One prominent building block to information security is cryptography. The science of cryptography is not as enigmatic as one might think. A variety of cryptographic techniques are used regularly in everyday life. For example, when you open your newspaper to the entertainment section you will find Daily Cryptogram, which is a word puzzle that involves unscrambling letters to find a hidden message. Also, although it is a dying art, many secretaries still use shorthand, or stenography, an abbreviated, symbolic writing method, to take rapid dictation. A form of cryptography is used even in knitting patterns, where directions are written in a coded form, in such patterns as K1P1 (knit 1, purl 1) that only an initiate can understand. These examples illustrate one important application of cryptography; the efficient and rapid transmittal of information, but cryptography also protects and verifies data transmitted via information systems (Micheal and Herbert, 2011).

The science of encryption, known as cryptology, encompasses cryptography and cryptanalysis as shown in figure 1.1. Cryptography, which comes from the Greek words kryptos, meaning “hidden,” and graphein, meaning “to write,” is the process of making and using codes to secure the transmission of information. Cryptanalysis is the process of obtaining the original message (called the plain text) from an encrypted message (called the cipher text) without knowing the algorithms and keys used to perform the encryption. Encryption is the process of converting an original message into a form that is unreadable to unauthorized individuals; that is, to anyone without the tools to convert the encrypted message back to its original format. Decryption is the process of converting the cipher text message back into plaintext so that it can be readily understood (Micheal and Herbert, 2012).

Cryptography is the art and science of protecting information from undesirable individuals by converting it into a form non-recognizable by its attackers while stored and transmitted (Hamdan et al., 2010). The aim of cryptography is to render a message incomprehensible to an unauthorized reader.

In the field of cryptography there exist several techniques for encryption and decryption. These techniques can be generally classified into two major groups, conventional (symmetric) and public key (asymmetric) cryptography as shown in figure 1.2. Conventional encryption is marked by its usage of single key for both the process of encryption and decryption whereas in public key cryptography separate keys are used. Further on conventional techniques are further broken in to Classical and Modern techniques (Anupama, 2014).

MSC Project Topics in Computer Science

Department: Computer Science (M.Sc)

Format: MS Word

Chapters: 1 - 5, Preliminary Pages, Abstract, References, Appendix.
Delivery: Email

No. of Pages: 87

NB: The Complete Thesis is well written and ready to use. 

Price: 20,000 NGN

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