They just mention they had access to the private key of the account so that makes sense how they got access. If FBI has broken SHA256, then Bitcoin is a done deal. I hope they share how they got access to the private key.

It'd be a big blow but not the end of the Bitcoin

what do you mean? if they broke sha256 in any meaningful way then people can skip (or significantly game) the whole mining thing...

The mining algorithm can just be changed with a hard fork.

The only think that would irrevocably kill Bitcoin is breaking private keys (ie discovering others private keys, or signing transactions without private keys). A fork could not solve it as there'd be no way to prove which coins you actually owned before the fork.

many people speculate that quantum computing would crack private keys in no time.

theres no speculation that this exists, but bitcoin wouldnt last in a commercial world of quantum algos

Wrong. IF there exists a general purpose formula (which isn't known yet) for all quantum problems, so secp256k1 is broken, then it would only reduce the complexity sqrt(N), from 2^256 down to 2^128. Which is unsolvable. (source: Stanford cryptography I course on coursera).

AND even if the elliptic curve cryptography of bitcoin is broken, say you can solve it in a year/month/week/day, the fact is most BTC unspent transaction outputs (UTXO's) are scripted "pay to public key hash".

The entity proving ownership of the UTXO needs to show a public key (that is so far unknown ... if they haven't reused this address before), AND this public key needs to hash into the address, AND the signature signed by the private key verified.

So if somebody announced they had solved secp256k1 and could break it in 1 week, your funds are safe. (1) They probably don't know your public key. Relax. And (2) You just wait for the BTC soft fork to support new crypto, then do a transfer to yourself. You transmit your transaction to the mempool (exposing your public key for the first time), and it will be mined in 10-30 minutes. Not enough time for the hackers to monitor the mempool and come up with a valid signature. Then your new UTXO is a different spend script for how to spend it next time using some new unbreakable crypto.

As long as there was some pre warning that such a quantum computer+algorithm was going to become available, Bitcoin would be able to fork, and users would be able to move their funds to quantum proofed (or at least hardened) wallets.

It surely depends on which aspect of SHA they would have broken, but the whole point of Bitcoin is the hash being completely unpredictable and requiring brute force. That's the Work in Proof of Work.

Bitcoin has contingencies in place to swap out any of its crypto algorithms.

They might be saving for bigger things, however this is a lot more than $3million. It's about holding the US economy hostage, as these will increase in frequency.

Indeed, stopping large-scale oil pipelines means US economy is held hostage, to a degree. Not all of it but some of it. Question is will it increase or not. This FBI action gives us some hope that criminals can be stopped.

Can be stopped? Doesn't sound like this is what happened here, the company paying the ransom is what stopped the hostage. The FBI simply recovered the ransom (and some more), but probably can't cover for the economic damage from the hold-up.

How is this holding the US economy hostage?

Randomware attacks on energy (oil and potentially electric grid) and hospitals. And that's only what we've seen so far.

"Randomware" sounds much more fun. Like Bertie Botts Every Flavor Beans, but for software. :-)

You may know it as "undefined behavior" ;)

XD