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by romaniv
2828 days ago
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>The usefulness of a consensus protocol is that no one party can be trusted to have the most up-to-date AND valid blockchain. Consensus protocols do not require mining. You can simply poll X random nodes and compare what they tell you. I don't understand what mining adds to the equation. Okay, instead of "I need to control 50% of all nodes" it becomes "I need to control 50% of all mining capacity". Is that the point of mining? To make inserting hordes of cheap lying nodes impossible? |
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You can poll multiple nodes and each one will give you a different answer because of message propagation times.
Mining fulfils two roles:
- identity management: To identify who is a trustworthy block producer in an anonymous and trustless network, mining introduces a cost to the block generation process and we use a game theory assumption that it serves as a barrier for attackers. This doesn't mean there aren't validation checks performed by other nodes in the network and the consensus forming rules themselves of course.
- consensus formation: In a distributed network, nodes are bound to disagree on which is the canonical chain out of two or more competing forks. The most common algorithm calculates the accumulated computational effort of each chain of blocks and picks the "heaviest" one, ie the one with the most work done on it. This has the nice side effect of ensuring economic finality for the transactions in those blocks.