Rotational Cryptographic Technique (RCT)

Abstract

A Security scheme based on Block Cipher is being designed where the Encoding and Decoding be prepared using Modular Adding, Rotational Shift operation and binary XNOR operation. The original message is stream of bits, & be presumed to be isolated into an amount of blocks having s bits in each of the them, where s be power of 3 (e.g. 3, 9, 27, 81, 243). An amount of 0’s be added at the MSB location of the stream for constructing whole numeral of bits odd in every block. For getting the cipher text the entire operation is done in two phases. In the first phase modular adding is done on neighboring blocks taking modulus of adding be 2^s. The amount restores the subsequent block, 1st block remnants unmoved. At the time of summing up, carry turned beginning the MSB be rejected. In the next phase left and right bit rotation are applied on the output stream and logical XNOR was executed on the result to get the cipher text. The technique be employed on blocks with changeable dimensions from 3 to 3ⁿ. For decryption, the order of XNOR operation & rotational shift will be reversed and modular decryption will be adopted.