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> By convention, everyone processing the blockchain looks to make sure that the new blockchain they get is a descendant of the previous blockchain they already

> By convention, everyone processing the blockchain looks to make sure that the new blockchain they get is a descendant of the previous blockchain they already have. This is not true. Bitcoin-esque blockchains are NOT append only. The only thing clients do is: 1) ensure the blockchain they have received is valid, and 2) that it is longer (more total PoW). If those conditions are met, they will consider that new chain the current chain. You can come up with a new, completely different sequence of blocks, send it to clients on the network, and get them to start using that new chain instead as long as it has more PoW.

geofft 9y ago
Oh, right. That seems like not a property you want in software releases - there shouldn't be a possibility of getting spoofed data (or metadata), either you get a signed release or no release at all. Bitcoin needs that because there's no signing authority. The key thing here is that there is an obvious central authority for software releases (the NPM registry, or GitHub, or Debian, or whatever), so proof-of-work-style systems are overkill because you don't fundamentally need decentralization. You could imagine some sort of decentralized first-come-first-serve software registry, but that doesn't seem obviously better than a central one.