If you have read my article on Ring-Trade Systems (check it out here), you know that I ended my argument on one assumption — A way to securely roll-up computationally intensive operations like ring-matching from L2 to L1. In the case of Loopring, the solution was a ZK roll-up. While I will save the Optimistic vs. ZK conversation to a potential future article, I do want to take some time to explain ZK, whose cameo in most articles consists of "…without getting into the mathematics…" and ".. it's basically magic…"