AN ODD-EVEN BLOCK CIPHER BASED CRYPTOSYSTEM THROUGH MODULO ARITHMATIC TECHNIQUE (OEMAT)
Debajyoti Guha · International Journal of Research in Engineering and Technology · 2013
In this paper, a new Cryptosystem based on block cipher has been proposed where the encryption is done through Odd Even Modulo Arithmetic Technique (OEMAT).The original message is considered as a stream of bits, which is then divided into a number of blocks, each containing n bits, where n is any one of 2, 4, 8, 16, 32, 64, 128, 256.The first and the penultimate blocks are then added where the modulus of addition is 2 n .The result replaces the penultimate block (say (N-1 th ) block), first block remaining unchanged.In the next attempt the second and the ultimate blocks (say N th block) are added and the result replaces the N th block.This process continues until all the blocks are executed.The modulo addition has been implemented in a very simple manner where the carry out of the MSB is discarded to get the result.The technique is applied in a cascaded manner by varying the block size from 2 to 256.The whole technique has been implemented by using a modulo subtraction technique for decryption.