Base for algebraic cryptanalysis based on combined representation of S‐box
Bekir Unlu · IET Information Security · 2018
This study reveals an organised algebraic view on the Advanced Encryption Standard (AES), and in particular the S‐box. A clear visualisation of algebraic expressions is granted for both the cipher part and the key schedule part of AES. Additionally, by introducing the combined representation of the S‐box, alternative methods can be constructed to serve algebraic cryptanalysis on AES. The process to obtain a combined representation of the S‐box, as a combination of four bits, the input value's multiplicative inverse and bytes in hexadecimal notion, may be of high importance for other proposed ciphers too built with layers of S‐boxes.