[ashtonkem]

If quantum computers break regular encryption, then the sudden collapse of Bitcoin would be the literal last of our worries. The inability to buy things using computers securely would be a much bigger problem, especially given how computerized banking is.

Good luck getting cash when your local bank is trying to figure out procedures that haven’t been used in a literal generation.

[gonzo41]

Bitcoin collapsing would be funny, in hindsight. Probably a pretty emotional event for some in the moment.

But banking is already not that secure. Credit cards suffer from massive ongoing fraud. Especially in places like the USA where chip systems are less common.

[ashtonkem]

There is still a pretty sizable difference between “a patchwork system that fails a lot in small ways” and “you can’t use a computer for anything financial, ever”.

[vmception]

I get the impression that the community would have enough consensus for a snapshot at a certain block number, and continue the chain with new quantum resistant keys

I think for the attacker with a quantum computer, they will need to steal low amounts for a long time so that people brush other user’s missing funds off as user error

But these investigations often do quickly give users the benefit of the doubt so I would see the network being at high alert really quickly

[cocoa19]

Chip is fairly common nowadays in the USA.

Fraud liability was shifted from card brands to retailers if they don't support chip. That was a big deal to start supporting it.

[anchpop]

Would it be any more complicated for banks than enabling this [0] (or whatever comes after it) in their webservers and asking visitors to use Chrome?

[0]: https://security.googleblog.com/2016/07/experimenting-with-p...

[ashtonkem]

Yes, by several orders of magnitude. The problem isn’t just browsers, it’s the massive pile of code that runs all these systems on the backend, many of which run on honest to god mainframes. You’re not going to flip a switch and get decades worth of software to run quantum proof encryption.

[jazzyjackson]

Wouldn't it just need to be the network transport that needs to be updated? I don't imagine the mainframe databases are encrypted-at-rest as it is, so how would quantum change anything there?

[ashtonkem]

Yes, it’s mostly network transit that’s the problem. The issue is that there is a lot of network transit behind the scenes that’s not going through nginx and a client browser.