In this paper, we propose a novel key-dependent MixColumn transformation to enhance the diffusion properties of block ciphers, specifically within the AES framework. The proposed method introduces dynamic variation into the MixColumn step by extracting a pseudo-random value from the round key, which is used to perform cyclic permutations on the MixColumn coefficients. This leads to the construction of a round-dependent transformation matrix, mathematically defined and proven to maintain invertibility over GF(2⁸). We provide a formal mathematical representation of the proposed model and analyze its diffusion characteristics, linear independence, and resistance to cryptanalytic attacks. Our approach eliminates static transformation patterns and introduces key-driven unpredictability, offering a promising direction for adaptive cryptographic primitives without increasing algorithmic complexity or requiring hardware modifications.
Enhancing block cipher diffusion: A mathematical approach to key-dependent mix column transformations
Authors
- Shiraz Naserelden Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia (UTM), Johor Bahru, 81310, Malaysia.
- Norma Alias Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia (UTM), Johor Bahru, 81310, and Center of Engineering Education, Universiti Teknologi Malaysia (UTM), Johor Bahru, 81310, Malaysia.
- Abdelrahamn Altigani Computer Information Science, Higher Colleges of Technology, 25026, Al Ain, Abu Dhabi, UAE.
- Maher Waheeb Computer Information Science, Higher Colleges of Technology, 25026, Al Ain, Abu Dhabi, UAE.
- Azmi Alazzam Computer Information Science, Higher Colleges of Technology, 25026, Al Ain, Abu Dhabi, UAE.
- Muawia A. Elsadig Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia.
- Hasan Abu Hilal Engineering Technology & Science, Higher Colleges of Technology, Abu Dhabi, UAE.
