Biham, Eli, and Stav Perle. “Conditional Linear Cryptanalysis – Cryptanalysis of DES With Less Than 242 Complexity”. IACR Transactions on Symmetric Cryptology 2018, no. 3 (September 4, 2018): 215–264. Accessed February 13, 2025. https://bmt.ub.rub.de/index.php/ToSC/article/view/7302.