Enhancing Security in Elgamal Cryptosystem Using Burrows-Wheeler Transformation and Run Length Encoding

Abstract

In day to day life, a secure communication is an important criteria over non-secure network channel. While transmitting the plain text, it is necessary to compress the text before encrypting the plain text, so that the speed of transmission of data, data storage space can be increased and also the redundancy of data in the plain text can be reduced. The process of encoding characters forms the different format so that fewer bits will be representing the original data whereby the size of the original data is reduced. Compression technique plays a vital role to compress the plain text. Though different compression techniques like lossy and lossless are available, the lossless compression technique can recover the original text from the reconstructed text. While compressing the larger amount of text, the reconstructed text must be identical to the original text. The Burrows-Wheeler Transform (BWT) technique of lossless compression is used in this paper to transform the plain text and the transformation permutes the order of characters. To reduce the redundancy and also to increase the efficiency of algorithm, move-to-front transformation is done by BWT. Further, the transformation code is compressed by using run length encoding so that the security will be increased after applying the cipher text in Elgamal public-key algorithm. The transmission speed, the security of data can be increased. Due to double security of the plain text, the hackers may not hack the code easily.