Researchers are regularly trying to figure out secure encryption algorithms so that the data transmitted over the computer networks are not intercepted by an unwanted entity. The two methods to encrypt data are Transposition and Substitution. Transposition refers to changing the position of characters in a given text. On the other hand, substitution is the process of replacing each character in the plaintext with some other character. One main concern area for researches is to analyze the existing encryption systems and overcome the flaws in them. In this paper, emphasis is paid on the enhancement of hill cipher algorithm. This algorithm uses simple substitution for encryption. The resistance of this algorithm is improved by introducing columnar and Myszkowski transpositions.

Cryptography, Encryption, Modified Hill Cipher, Columnar Transposition, Myszkowski Transposition

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