A New Polybit Shuffling Encryption and Decryption Algorithm Based on N Dimensional Encryption-Decryption Matrix

This paper elaborates polybit shuffling encryption and decryption algorithm based on N Dimensional encryption-decryption matrix which is an attempt to improve over the Classical Playfair Cipher. The unique feature of this algorithm is that it retains the simplicity of Classical Playfair Cipher but increases the robustness against crypto-attack by many folds. Moreover this algorithm can be used on any type of files as it is capable of encrypting binary files because this algorithm, instead of using characters, uses chunks of several bits or bytes to represent data values. The proposed polybit encryption and decryption algorithm uses an N-Dimensional encryption-decryption matrix. The encryption-decryption matrix is first filled up by the keywords (passwords) and then by the rest of the possible chunk values. Encryption is done on N number of chunk values as a block thereby ensuring higher level of encryption and security. Encryption is done by choosing a linear transformation function of the position co-ordinates of the N chunks of a block. The transformation function can be chosen depending upon the need for speed of encryption and degree of security needed. Decryption is also simple as one has to use reverse transformation function on the encrypted file using again N chunks as a block. Finally it may be noted that just by increasing the dimensions M and N we can combat against the advancement of computational power and thus against advanced crypto-attack.