Cascaded Spin Shuffle: A Transposition Cipher Using Spin Motion and Grid Cascading

This paper proposes a transposition cipher algorithm based on cascaded spin shuffle (CSS).The plaintext is shuffled on a two-dimensional grid using CSS, where the letters are arranged based on spin motion, creating diverse permutations.The cascading technique prevents dead-ends at the grid's edge cells by wrapping around to the opposite side, resulting in complex permutations and allowing flexible placement of the initial spinning point.Unlike traditional transposition ciphers, such as columnar, route, and rail fence, which suffer from fixed-period repetition, the CSS technique avoids such limitations using the spinning and cascading mechanisms.Compared to the Advanced ciphers' Permutation Box (P-Box), which suffers from predictability with frequent patterns, key management, and high computation requirements, CSS offers a novel approach with unpredictable, arbitrary distribution and a variable-length key that enhances key space and simplifies implementation.The results of the proposed cipher using randomly generated files and keys showed that the proposed cipher maintains low correlation, Pearson, Spearman, Chi-Square, and Kolmogorov-Smirnov values.Compared to the existing ciphers, the proposed cipher implements a single round, thus reducing the time requirements.In terms of security, the proposed CSS algorithm defeats the n-gram statistical analysis and the simple cipher guessing.The proposed cipher was also analyzed for plaintext and key sensitivity.The performance analysis indicates its robustness and effectiveness.