https://medium.com/cryptoblog/what-is-lattice-based-cryptography-why-should-you-care-dbf9957ab717

Above is a really high-level and gentle intro to Lattice crypto. We have never talked about Elliptic Curve in our class, let alone this Lattice monster. But, I hope you could spend 5 min to give the medium blog a read. You will see the “hard problems” we talked about for asymmetric crypto and why it is really hard to prove that those problems are actually hard. Yet, Lattice crypto takes a different approach and somehow it is post-quantum safe, as I have been told. You probably can guess now that some of the “hard problems” are not post-quantum safe, although RSA might still be secure if we use a 32GB private key…

Anyway, sorry for this long due post. Stay safe~