the power is needed because trustless distribsuted ledger is mathematically impossible.
So there has to be some mechanism that actually prevents someone being able to just change anything at will. This is the mathematical impossibility part. What bitcoin does to get around it is to (artificially) make it cost resources to write into the ledger by making everyone solve a random useless puzzle. And with each block depending on the one preceding it, changing implies also changing all the subsequent ones.
This of course assumes that the chain is ever growing, otherwise the attacker just needs time to catch up. Bitcoin’s security guarantees come from ensuring the network keeps growing faster than any one single entity could write to it. The only thing that keeps anyone from writing whatever is that they just can’t do it fast enough.
This implies that the network is only (probabilistically) secure as long as there are people mining it. If people stop mining, bitcoin instantly loses all of its security.
It then follows that the security of the chain depends on its ability to keep its users wanting to mine it. This is handled by it being a currency. something that humans would have a psychological need to hoard.
This is also why any non-cryptocurrency application of blockchain simply cannot possibly work.
the power is needed because trustless distribsuted ledger is mathematically impossible.
So there has to be some mechanism that actually prevents someone being able to just change anything at will. This is the mathematical impossibility part. What bitcoin does to get around it is to (artificially) make it cost resources to write into the ledger by making everyone solve a random useless puzzle. And with each block depending on the one preceding it, changing implies also changing all the subsequent ones.
This of course assumes that the chain is ever growing, otherwise the attacker just needs time to catch up. Bitcoin’s security guarantees come from ensuring the network keeps growing faster than any one single entity could write to it. The only thing that keeps anyone from writing whatever is that they just can’t do it fast enough.
This implies that the network is only (probabilistically) secure as long as there are people mining it. If people stop mining, bitcoin instantly loses all of its security.
It then follows that the security of the chain depends on its ability to keep its users wanting to mine it. This is handled by it being a currency. something that humans would have a psychological need to hoard.
This is also why any non-cryptocurrency application of blockchain simply cannot possibly work.