Salutations fellow stackers.
I've spent the last month researching the threat of quantum computing to Bitcoin, and how this threat could be concretely addressed without any new cryptographic assumptions, using one particular flavor of post-quantum cryptography: hash-bashed signature schemes. This article is the finished product of that research - you might call it a digest of my findings.
At the end of the article, I propose a novel option called "Digests as Secret Keys" (DASK) which uses these algorithms to add a post-quantum fallback option to regular bitcoin addresses, without relying on complex new technology like ZK-STARKs (that will be my next focus). This upgrade could be implemented today, but would defer consensus changes until a practical quantum computer appears close at hand. More discussion about that here.