Performance And Security Enhanced Improved Hill Cipher

Abstract

Hill cipher is one of the classical ciphers which is considered as a secured one till date apart from its vulnerability of known plaintext attack. Because of its simplicity, in recent days also it is used as one of the building block of cryptography and steganography based algorithms. Many research articles are available to minimize the known plaintext attack vulnerability of Hill cipher. One of the research works suggests to use a second key which varies exponentially with block numbers of the plaintext. Though the proposal is very simple, it is a time consuming process. Furthermore, it has some weak blocks which deteriorates the security. In this research article both issues are rectified by the inclusion of a look-up-table method. The proposed method saves power and enhances the speed by slightly compromising with area. Implementation results show that the proposed method reduces the performance complexity from O(nlogn) to O(n).