What does post-quantum cryptography actually mean in plain English?

[RightNutter]

Seeing this term everywhere lately, what does post-quantum cryptography actually mean without the jargon?

[Tia88]

It just means encryption methods designed to stay secure even against a future quantum computer, as opposed to the encryption most systems use today, which relies on math problems that are hard for normal computers but would become solvable for a sufficiently powerful quantum one

Instead of number factoring, which is what quantum computers are specifically good at breaking, post-quantum methods lean on different kinds of math problems, things like error correcting codes or lattice structures, that don't have a known quantum shortcut yet

[202694]

Basically future proofing your encryption before the threat actually arrives rather than scrambling to fix it after

[HenryThierry]

NIST already picked a handful of these as official standards a while back, some companies have already started rolling them out quietly in the background