International forum of researchers Students and Academician
Generally in Hill cipher modifications interweaving are considered. This paper reveals that the strength of this cipher is due to non-linear transformation of interweave transposition and shifting used in them. The impact of number of iterations on the avalanche effect is investigated. The interweaving of the resulting plaintext, at each stage of the iteration, and the multiplication with the key matrix followed by transposition and shifting leads to confusion and diffusion. From the cryptanalysis performed in this investigation, the authors have found that the cipher is a strong one. Here, they propose Hill cipher modifications using Transposed Interweaved Shifting with significantly less computational complexity.