A Complex Polyalphabetic Cipher Technique: Myanmar Polyalphabetic Cipher

Abstract

The rapid development of electronic exchange of digital information increases the importance of information security in storage and transmission of data on public communication network. Cryptography has emerged as a solution that plays a key role in the security of information against malicious attacks. There are various cipher techniques in cryptography, such as monoalphabetic cipher, polyalphabetic cipher, etc. to support data confidentiality as security mechanisms. They are methods of enveloping plain text message into cipher text protecting it from adversaries. The process of encryption of alphabets is the converting original message into non readable form. The Vigenère cipher is one of the most common basic cipher techniques. It is a polyalphabetic cipher technique which uses the Vigenère table for the process of enveloping English alphabets. But Vigenère cipher is longer vulnerable to Kasiski and Friedman attacks based on letter frequency analysis. Thus, in this paper we propose a polyalphabetic cipher that is a new encryption and decryption technique with diffusion and confusion properties based on the concept of the complex cipher used by combining of Vigenère cipher with Affine cipher for the increase of data security in data storage and transmission on public communication networks. Then, our proposed technique is extended by designing based on Myanmar alphabet characters for the increase of data security for Myanmar language. This cipher technique transforms the plain text message in Myanmar alphabet characters into the cipher text in Myanmar alphabet characters using the key in Myanmar alphabet characters.