2 ms·

From the page I linked: In distributed networks, a transaction has "finality" when it's part of a block that can't change. "To do this in proof-of-stake, Casp

From the page I linked: In distributed networks, a transaction has "finality" when it's part of a block that can't change. "To do this in proof-of-stake, Casper, a finality protocol, gets validators to agree on the state of a block at certain checkpoints. So long as 2/3 of the validators agree, the block is finalised. Validators will lose their entire stake if they try and revert this later on via a 51% attack." In ETH2 2/3 of 128 randomly selected validators have to agree. You also get slashed if your validator goes offline, so they factored for that case: https://ethereumprice.org/guides/article/eth-2-staking-risks/ https://ethereumprice.org/guides/article/eth-2-staking-risks... And at least for the beacon chain you have to sync the whole chain to your node before you can begin validating.

alexmingoia 6y ago
Determining a valid block isn’t the same thing as determining the correct chain. A node validates blocks by staking, but how does the node know it’s validating a block on the correct chain? As far as I can tell, PoS projects don’t have a trustless solution to this problem. Imagine a net split, where the network becomes briefly partitioned. Nodes in each partition would keep adding blocks. When the network converges, there would be two conflicting chains. Using proof-of-work the chain with the most work (longest chain) is the valid chain. Another scenario: Using proof-of-stake I can create my own alternative chain easily (if I don’t want stake money I could create new genesis block), and broadcast blocks to nodes that join the network. When those new nodes receive blocks from conflicting chains, which one is correct? From what I understand of Ethereum, new nodes have to choose trusted nodes when they join the network. I wonder, if one is going to consider trust a non-problem, then why stake at all? A network like Nano works the same way, by trusting a quorum of voting nodes, but there’s no staking or inflation, which has the benefit of allowing anyone to participate without the rich getting richer.

alexmingoia 6y ago

Determining a valid block isn’t the same thing as determining the correct chain. A node validates blocks by staking, but how does the node know it’s validating a block on the correct chain? As far as I can tell, PoS projects don’t have a trustless solution to this problem. Imagine a net split, where the network becomes briefly partitioned. Nodes in each partition would keep adding blocks. When the network converges, there would be two conflicting chains. Using proof-of-work the chain with the most work (longest chain) is the valid chain. Another scenario: Using proof-of-stake I can create my own alternative chain easily (if I don’t want stake money I could create new genesis block), and broadcast blocks to nodes that join the network. When those new nodes receive blocks from conflicting chains, which one is correct? From what I understand of Ethereum, new nodes have to choose trusted nodes when they join the network. I wonder, if one is going to consider trust a non-problem, then why stake at all? A network like Nano works the same way, by trusting a quorum of voting nodes, but there’s no staking or inflation, which has the benefit of allowing anyone to participate without the rich getting richer.