[zazagura]

Not really. Your bank (and the whole web) can easily switch to a quantum resistant encryption algo when time comes.

For Bitcoin this is much harder.

[rolltiide]

Its not much harder for bitcoin...

The community will just do a blockchain snapshot of balances at an agreed upon block and start a new distributed ledger with quantum resistant encryption

Snapshots have been done hundreds of times

[zazagura]

Everybody will need new private keys.

What do you do with old coins? Satoshi's one for example? Or lost coins that nobody has the key for?

Do you set a threshold day, after which all unclaimed coins are just marked destroyed forever? If not, how do you know someone claiming some coins didn't use a quantum computer to get the key?

[gruez]

>Do you set a threshold day

yeah pretty much.

>What do you do with old coins? Satoshi's one for example? Or lost coins that nobody has the key for?

If those coins hasn't been touched for decades, despite widespread announcements of pre-quantum cryptography (presumably it wouldn't happen overnight), it's safe to say that nobody is going to claim them.

[rolltiide]

Dont treat any address differently

[rolltiide]

You wont know that, you will provide the tools and also new accounts will have assurance and regenerate confidence in the system

So we have moved from concluding that bitcoin use is an irreparably flawed concept to a method of maintaining viability of the concept

[xiphias2]

It's easy to add a quantum resistant algorithm, but as it's much more expensive to verify and takes more block space, the transaction fees will be much higher. Transitioning is a huge political problem as well.

[londons_explore]

It'll be politically easy. Nobody wants someone else able to steal their money.

[sroussey]

> The community will just do ...

This is the funny thing about decentralized services. They require centralized action. Not saying it is good or bad, but it is... different.

[rolltiide]

It requires community consensus thats the opposite of centralized

Anyone can make a snapshot, assigning value to it is not centralized

[sroussey]

I said centralized action. Community consensus sounds nicer, but simultaneous action is required.

I don’t imagine this is other settings... “I only do breaking changes on my api so let’s have everyone change their client at midnight”.

Imagine if we all changed implementations of SQL at once!

Actually, we changed the meaning of the $() function inside the devtools console across all browsers at the same time. That was fun. :)

[rolltiide]

No thats not necessary.

People just add flags in their mining protocol that only trigger when a threshold is reached. The last Segwit changes needed a percent change of closer to 90% just to trigger the next change.

We are only assuming that consensus would be reached quickly given the scenario presented. It would be irresponsible to design it to need simultaneous action. People would have to considering to stop using the bitcoin network for X,000 blocks while consensus is being reached, and only until it is reached.