Z. Bao, L. Ding, J. Guo, H. Wang, and W. Zhang, “Improved Meet-in-the-Middle Preimage Attacks against AES Hashing Modes”, ToSC, vol. 2019, no. 4, pp. 318–347, Jan. 2020, doi: 10.13154/tosc.v2019.i4.318-347.