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> Re your PS, there will still be an old and new consensus blockchain no matter how fast you calculate the replacement. Yes, of course. In fact, at any point i
by cs702 9y ago
> Re your PS, there will still be an old and new consensus blockchain no matter how fast you calculate the replacement.
Yes, of course. In fact, at any point in time there are always multiple blockchains, one for every miner burning energy to add a new block.
However, only the longest blockchain (with the greatest proof-of-work) is valid. As soon as there's a longer valid blockchain, the miners discard their individual work-in-progress blockchains and switch to the one with the most proof-of-work.
That longest blockchain is the Bitcoin blockchain. That is the blockchain one would have to modify to alter the transaction history in the Bitcoin network without forking.
FWIW, I don't think we disagree; I feel like we've been talking about slightly different things until just now.
- maxerickson 9y agoWe are kind of talking about different things. I'm talking about how at the protocol level the contents of the longest chain do not matter, it is by rule the "consensus blockchain". It naturally flows from there that as long as you can calculate blocks faster than the network, you can rewrite past transactions, with the speed difference restricting how far back you can rewrite. There's no need to do it in an instant and doing it in an instant isn't any different than doing it more slowly (other than the amount of hidden hash power revealed).
- cs702 9y agoYes, I agree.