ZKPOK is a challenge I made while learning Zero Knowledge Proofs on zk-learning.org. I was watching the first lecture video, I came across with the interactive proof for quadratic residues at 20:00. This made me ponder - it should be easy to apply Fiat-Shamir transform to make this non-interactive. Let’s also use MD5 so that it could be vulnerable. Hours later, this challenge appeared without a proper solve script. Surprisingly, the challenge ended up having three solves, which makes this t...
