Not how it works as far as I know. If people start mining with a quantum computers the difficulty will increase making it even more secure (one of bitcoins main features). Traditional computers will drop out due to lack of rewards and more powerful quantum computers will enter and compete with the original quantum computers and the cycle continues. It’s a self balancing system.
But you have control of the network with a majority of mining right? So it’s very possible that one or more organisations could control it for long enough that it’s not trusted?
I’m not really a great source for this stuff but I would assume that the quantum computer would have to be more powerful than all of the other mining compute combined for that to happen. Then it would have to be so far ahead that no new quantum computers were coming online to compete against it.
The other part is incentive. If you want to take over 50% of the network the incentive wouldn’t be to double spend because once it’s detected the price collapses due to lack of trust, bitcoins fundamentals change and it’s no longer decentralised effectively making it another centralised shitcoin. There could be incentive for a government to do this or a rival currency but bitcoin is fundamental to all crypto currencies so they would be damaging themselves greatly in the process.
I can’t answer your proof of stake question with any confidence
QC would be completely devastating to bitcoin. Anyone with a sufficient QC could break any block of the bitcoin chain they want, essentially giving all the bitcoins to themselves. There are other cryptocurrencies that are quantum-resistant, but bitcoin itself would be done.
I would assume in the face of that the bitcoin network would have to change its consensus to include quantum resistance. I think this is possible but not sure
Not how it works as far as I know. If people start mining with a quantum computers the difficulty will increase making it even more secure (one of bitcoins main features). Traditional computers will drop out due to lack of rewards and more powerful quantum computers will enter and compete with the original quantum computers and the cycle continues. It’s a self balancing system.
But you have control of the network with a majority of mining right? So it’s very possible that one or more organisations could control it for long enough that it’s not trusted?
And how does proof of stake work cryptography?
I’m not really a great source for this stuff but I would assume that the quantum computer would have to be more powerful than all of the other mining compute combined for that to happen. Then it would have to be so far ahead that no new quantum computers were coming online to compete against it.
The other part is incentive. If you want to take over 50% of the network the incentive wouldn’t be to double spend because once it’s detected the price collapses due to lack of trust, bitcoins fundamentals change and it’s no longer decentralised effectively making it another centralised shitcoin. There could be incentive for a government to do this or a rival currency but bitcoin is fundamental to all crypto currencies so they would be damaging themselves greatly in the process.
I can’t answer your proof of stake question with any confidence
QC would be completely devastating to bitcoin. Anyone with a sufficient QC could break any block of the bitcoin chain they want, essentially giving all the bitcoins to themselves. There are other cryptocurrencies that are quantum-resistant, but bitcoin itself would be done.
I would assume in the face of that the bitcoin network would have to change its consensus to include quantum resistance. I think this is possible but not sure