nehanBitcoin and quantum computing
https://nehanarula.org/2026/04/03/bitcoin-and-quantum-computing.html
The mostly likely quantum attack on Bitcoin will be a catastrophic transfer of large wallets to burn addresses along with a massive short position. No need to worry about washing stolen coins when you can just enjoy your "well timed" legal short position's windfall.
Interesting, considering the extra liability / (stability) volatility that bitcoin options provide when making ROI and hashrate calculations, this can be a triple threat.
Like publicly destroying ivory /poppy stockpiles while simultaneously holding puts/futures on correlating pharmaceutical financial instruments.
two things:
1) Short markets in Bitcoin don't have unlimited depth, and the centralized ones are KYC'd so there's some risk there
2) What if it doesn't tank the price? One thing people have suggested is just burning all the vulnerable coins[1]; it reduces supply so maybe the price will... go up? The point is there's uncertainty.
One thing that is not addressed: say this quantum attack happens tomorrow and everyone agrees it was an attack, what would prevent the community (miners, node operators, and users) to hard fork the chain at a snapshot before the attack, patch the protocol, and call that Bitcoin? There would be loss of value of course, but it is not unrecoverable.
It’s worth remembering that Ethereum forked for much less (not even a bug in the protocol, but a bug in a private application running on the protocol) and nobody seems too upset about it a decade later.
A hard fork implies a difference in consensus rules, and what do you propose that difference be?
Existing wallets need to actively commit to some PQ signature mechanism, prior to Q-day.
Even if Q-day means there is a way to deterministically retrieve any private key from a public key (is that what it means? or is the blast radius of q-day contained? This is a bit above my level of cryptography), I’m sure we could come up with something to minimize the damage. In the worst case, it might involve a claim process with an authority or consensus mechanism to prove who the rightful owner of the funds is and revert the unauthorized transactions on the new chain.
Yes, this is not ideal! But if the wallet conversion requires active participation, preemptive measures are also not ideal.
In theory nothing prevents that but it would be so contentious that the backlash (e.g. 90% drawdown) may be even worse than just letting the hacks stand.
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Somewhat ironic question, but as ETFs holdings of BTC continue to grow, is there a possibility that the custodians of those ETFs start to have a backup plan for ETF holders or create an alliance to push a fork forward? The management fee those companies generate is non-trivial, so they're incentivized to stay ahead of this.
Now, of course, the irony here would be traditional finance infrastructure winning out over decentralized, which could definitely deal a psychological blow to BTC's perceived value... but it's something I've been thinking about lately as this existential threat rises on the horizon.
The thing that supposedly sets Bitcoin apart from other cryptocurrencies is that it's deflationary and 'immutable', in that Satoshi is gone forever and any deviation of Bitcoin from his golden idea will result in undermining its essence. If Bitcoin can get quantum-attacked then, from a technical point of view, nothing will be lost. The Bitcoin core devs can issue a word-of-god statement stating that they'll roll back the chain to before the attack, and all is well. Then they'll change the cryptography. But at that point, is it still Bitcoin? Because you've undermined the immutability. If the core devs can just say "this core property of Bitcoin is now something completely different", who's to say that they won't change their minds about the deflationary nature in the future? All credibility will be lost. Now, if you accept that, is perhaps all credibility lost already? ...
This was already pretty well hashed out (heh) during the 'core'/'cash' issue when there was an attempt to fork in an expanded the block size. Both chains still exist. Bitcoin operation is entirely up to the miners to determine the heaviest chain, and that's like two entities (the number of entities required is called the Nakamoto coefficient). It's not magic, but there is a huge cult built up around it by scammers, rubes, opportunists and speculators.