A Modified Playfair Cipher Involving Interweaving and Iteration

Abstract

Abstract-In this investigation, we have generalized and modified the Playfair cipher into a block cipher. Here, we have introduced substitution, interweaving and iteration. The cryptanalysis and the avalanche effect carried out in this analysis markedly indicate that the cipher is a strong one, and it cannot be broken by any cryptanalytic attack.Index Terms-interweaving, inverse interweaving, substitution matrix.

An Efficient Binary Playfair Algorithm Using a 4×4 Playfair Key Matrix

“…Use of multiple iteration and character substitution further increases the security. These interweaving and iteration actually leads to lots of confusion and diffusion [4] [5]. These modifications are useful for text encryption, but for modern day encryption of multilingual character or media files, the algorithm must be modified to support binary file encryption.…”

“…Despite its proven efficiency the algorithm lacks on several areas. Over the years several attempts have been made to modernize the algorithm [2], [3], [4], [5], [6], [7], [8], [9], [10] to increase its acceptances by eliminating its limitations. This paper provides a new solution approach to overcome the shortcomings of the Playfair algorithm.…”

Comparing Classical Encryption With Modern Techniques

“…DES enhances the structure of S-DES by increasing the key size from 10-bits to 64-bits out of which its affective length is 56-bits [8].16 rounds are introduced with each round containing XOR, substitutions and permutations for 16 rounds 16 keys are generated each of 48-bits which strengthens the security of this algorithm further, in terms of processing DES is 3 times faster than 3 DES [9].DES takes plain text in 64-bits of block these 64-bits are divided in to 32-bits each the right half of 32-bits goes through the expansion block which increase the bit count from 32 to 48-bits by reusing some bits after expansion block comes XOR operation with sub-key which is also of 48-bits result of this operation is again of 48-bits, these 48-bits now goes in to 8 S-boxes the 48-bits are divided into 8 parts of 6-bits each going in to S-box1 to S-box8, the overall result of S-box substitution is reduced from 48 to 32-bits which is then XOR with the left half of the initial plaintext block to give a 32-bit result which is placed on right and the initial right half of the block is placed at left to get the 64-bit output of its round similarly this output of 1st round becomes input of the 2nd round and same procedure is pursued till the 16th round, after 16th round there is a 32 bit swap and finally the bits are placed in inverse permutation table to get the encrypted message, reverse method is applied to yield the result [7].…”

Secured Data Transmission Using Modified LEHS Algorithm in Wireless Sensor Network

“…U. K. Sastry et al [8]- [10] customized the original Hill cipher by including interweaving, interlacing and iteration. Modified Hill cipher [8] [9] have avalanche effect and are believed to defend against any cryptanalytic attack. Many of the modifications such as how the interweaving and interlacing along with the iteration will strengthen the Hill cipher and the necessity of the number of iteration to be 16 are not argued.…”