Grošek, Otokar, and Július Šiška. “Semigroup of Matrices over GF{2^s} and Its Relation to AES”. Computing and Informatics 22, no. 5 (February 20, 2012): 417–426. Accessed February 2, 2026. http://147.213.75.17/ojs/index.php/cai/article/view/462.