A Complex Polyalphabetic Cipher Technique: Myanmar Polyalphabetic Cipher

The rapid development of electronic exchange ofdigital information increases the importance of informationsecurity in storage and transmission of data on publiccommunication network. Cryptography has emerged as asolution that plays a key role in the security of informationagainst malicious attacks. There are various cipher techniques incryptography, such as monoalphabetic cipher, polyalphabeticcipher, etc. to support data confidentiality as securitymechanisms. They are methods of enveloping plain text messageinto cipher text protecting it from adversaries. The process ofencryption of alphabets is the converting original message intonon readable form. The Vigenère cipher is one of the mostcommon basic cipher techniques. It is a polyalphabetic ciphertechnique which uses the Vigenère table for the process ofenveloping English alphabets. But Vigenère cipher is longervulnerable to Kasiski and Friedman attacks based on letterfrequency analysis. Thus, in this paper we propose apolyalphabetic cipher that is a new encryption and decryptiontechnique with diffusion and confusion properties based on theconcept of the complex cipher used by combining of Vigenèrecipher with Affine cipher for the increase of data security in datastorage and transmission on public communication networks.Then, our proposed technique is extended by designing based onMyanmar alphabet characters for the increase of data securityfor Myanmar language. This cipher technique transforms theplain text message in Myanmar alphabet characters into thecipher text in Myanmar alphabet characters using the key inMyanmar alphabet characters