Grassi, Lorenzo, et al. “The Legendre Symbol and the Modulo-2 Operator in Symmetric Schemes over Fnp: Preimage Attack on Full Grendel”. IACR Transactions on Symmetric Cryptology, vol. 2022, no. 1, Mar. 2022, pp. 5-37, doi:10.46586/tosc.v2022.i1.5-37.