[bawolff]

> If Bitcoin is broken then your bank encryption and everything else is broken also.

Its a lot easier for your bank to change encryption methods than it is for bitcoin. Presumably you mean TLS here (where else do banks use encryption? Disk encryption?). People are already deploying experiments with quantum-proof TLS.

> 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.

This is probably the wrong way to look at it. Once you start multiplying numbers together (for real, using error corrected qubits), you are already like 85% there. Like if this was a marathon, the multiplying thing is like a km from the finish line. By the time you start seeing people there the race would already be mostly over.

[cyberpunk]

I still don’t really get the argument, like okay this extremely rich theoretical attacker can obtain the private key for the cert my service uses, and somehow they’re able to sniff my traffic and could then somehow extract creds. But that doesn’t give them my 2fa which is needed to book each transaction, and as soon as these attacks are in the wild anti fraud/surveillance systems will be in much harder mode.

I don’t see QC coming as meaning bank accounts will be emptied.

disclaimer: I work at a bank on such systems

[bawolff]

My bank definitely doesn't require 2FA on every transaction. It only requires it to log in. I guess other people have more security concious banks then me.

Even still, i think there is some benefit to attackers being able to passively monitor connections. Getting the info neccesary to conduct some other type of fraud outside of the system. Lots of frauds live or die on knowing enough about the victim's financial situation.

However it really doesn't matter, when it happens we will just switch to different encryption.

[i2km]

It’s turning into a bit of a grift now. So many crypto agility “consultants “ popping up with their slop graphics. Never mind the fact that even if a relevant quantum computer is built it will still cost the user millions of dollars to break each RSA key pair…

[bawolff]

I dont neccesarily think it would cost millions per key pair. Hard to say with the technology so immature, but it seems like the sort of thing with huge upfront costs but low marginal costs. Once you have a QC you dont have to build a new one for the next key pair.