Enjoyed re-reading this long thread (beginning in 2017) where Daira-Emma Hopwood, Sean Bowe, Ariel Gabizon, HarryR, Dmitry Khovratovich, dice2-win, Tomer Ashur, Daniel Lubarov, and Weikeng Chen collaborated on the new secure hash functions like Poseidon. https://github.com/zcash/zcash/issues/2233