[xigoi]

Who is going to replace it? There is no central authority.

[nodoll]

None required. Once the vulnerability is known, everyone will be incentivized to migrate to the new coin.

[xigoi]

Sure, but you’ll lose all your existing money.

[nodoll]

No, the new coin will be exactly as valuable as Bitcoin, ensured by the community consensus. That is the whole point.

[IAmGraydon]

You clearly don't understand. Once the BTC cryptography is compromised, there is now way to prove chain of custody, so there is no way to prove who has how much bitcoin and assign it to a new coin. Literally, in an instant, the price of BTC goes to zero.