> I think by value (i.e. number of BTC), adoption of quantum safe schemes could be pretty strong, even if there is like a 4KB signature on spend. Many people and entities with >1,000 BTC want it to be quantum safe and will jump through hoops to get it. So what? If/when a CRQC is “happening soon” we’ll (hopefully) have a decent PQC scheme and will be soft-forking that in. The large custodians can move relatively fast. Doing any kind of fork to protect them now seems entirely uninteresting cause they’re not gonna be materially at risk in any case. If we’re talking about doing something, it has to be something “average” (long-term-storage) wallets will adopt. > I really do not see why people would want to put money in a quantum safe tapleaf, that is also quantum vulnerable by the key path, when P2WSH is more quantum safe. Or maybe P2WSH with BIP 39 12/24 words is the most quantum safe place to keep your Bitcoin, because like you say, there may be post quantum redeption methods. This gets back to my point about the eventual decision on freezing being important for short-term decisions. If we take as an assumption that the community will freeze non-quantum-safe coins (I think this is a very safe assumption!), the a quantum safe tapleaf is just as safe as any other quantum safe output. If we don’t assume that, then I don’t think any option we have would get material adoption. > And I do not have the faintest idea how quantum technology will develop, not at all, gradually or suddenly/unexpectedly. I have no idea. Do you? If its unexpectedly, then maybe we cant get consensus for a freeze/burn until its too late. The only other way I can see would be to get consensus by "letting the market decide". e.g. 95% of all active Bitcoin is already in quantum safe outputs. I can see that as a catalyst for consensus It’s possible, but from all the reporting and speculation I’ve seen, it seems highly unlikely that we’ll get a sudden breakthrough leading to a CRQC. Progress has been very slow and steady, while breakthroughs happen, they don’t lead to a massive step function but rather have led to continued incremental improvement. It’s an assumption but imo a rather safe one.(Matt Corallo 🟠)