Gao, Yuan, Chun Guo, Meiqin Wang, Weijia Wang, and Jiejing Wen. 2020. “Beyond-Birthday-Bound Security for 4-Round Linear Substitution-Permutation Networks”. IACR Transactions on Symmetric Cryptology 2020 (3):305-26. https://doi.org/10.13154/tosc.v2020.i3.305-326.