Lossy CSI-FiSh: Efficient signature scheme with tight reduction to decisional CSIDH-512 by El Kaafarani, A, Katsumata, S, Pintore, F

“…Recently, Beullens, Kleinjung, and Vercauteren (Asiacrypt'19) provided the first practical isogeny-based digital signature, obtained from the Fiat-Shamir (FS) paradigm. …”