alt Hacker NewsOne thing I find rather amazing about all of this is the degree to which the Bitcoin community has tried, for years, to claim that quantum computers will be another other than a complete break.
Sure, it takes a pretty nice quantum computer or a pretty good algorithm or a degree of malice on the part of miners to break pay-to-script-hash if your wallet has the right properties, but that seems like a pretty weak excuse for the fact that the entire scheme is broken, completely, by QC.
Does there even exist a credible post-quantum proof protocol that could be used to “rescue” P2SH wallets?
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> the Bitcoin community has tried, for years, to claim that quantum computers will be another other than a complete break.
Who specifically is claiming this? Satoshi literally mentioned the need to upgrade if QC is viable on bitcointalk in 2010.
Call me crazy, but I think if bitcoin is ever broken they're more likely to move to a centralized ledger than a more secure decentralized ledger. Roughly nobody invested in bitcoin cares about the original mission, they just care about their asset prices.
On the brightside at least we'll have a clear indicator for when quantum computers actually arrive.
The problem here is the word "will". Because they don't exist.
If Bitcoin is broken then your bank encryption and everything else is broken also.
As far as I know quantum computers still can't even honestly factor 7x3=21, so you are good. And the 5x3=15 is iffy about how honest that was either.
https://news.ycombinator.com/item?id=45082587
Bitcoin uses 256-bit encryption, it's a universe away from 5x3=15.
The best proposal I have heard for rescuing P2SH wallets after cryptographically relevant quantum computers exist is to require vulnerable wallets to precommit to transactions a day ahead of time. The precommitment doesn't reveal the public key. When the public key must be exposed as part of the actual transaction, an attacker cannot redirect the transaction for at least one day because they don't have a valid precommitment to point to yet.