https://en.wikipedia.org/wiki/AKS_primality_test though it's number theory, and concerned with numbers of size n, rather than lists of length n.
Also relevant: https://www.cs.yale.edu/homes/aspnes/pinewiki/Derandomizatio...
Also relevant: https://www.cs.yale.edu/homes/aspnes/pinewiki/Derandomizatio...
They were talking about not reading a lot of the input, so that's not it.