3 ms·
Here's why GHOST supports shorter block times for the same security. In Bitcoin, the chosen block is the one with the most hashpower in the linear chain behind
by DennisP 7y ago
Here's why GHOST supports shorter block times for the same security.
In Bitcoin, the chosen block is the one with the most hashpower in the linear chain behind it. Abandoned forks contribute nothing to that.
With GHOST, the chosen block is the one with the most hashpower descended from it, in all forks. This way all the forks contribute to a block's security.
With a linear chain, propagation time is an issue. If blocks are too short it's more likely that miners will find more than one candidate block, causing the work on abandoned blocks to be wasted. With GHOST, no work is wasted.
The original GHOST paper, which proposed the algorithm as a modification to Bitcoin, has some math to calculate, for a given propagation time, the block time that would produce equivalent security to a linear chain. It was significantly shorter.
- codexon 7y agoAs far as I can tell, GHOST is only used to mitigate high hash power loss when confirmation times are lowered to 15 seconds. Orphaned blocks are very rare in Bitcoin. https://www.blockchain.com/btc/orphaned-blocks?offset=0 https://www.blockchain.com/btc/orphaned-blocks?offset=0 Even if you somehow saved all this wasted hash power, you would only maybe increase hash power by less than 1%!!! Read my comment here for more details. https://news.ycombinator.com/item?id=21550997 https://news.ycombinator.com/item?id=21550997
- DennisP 7y agoSounds like we vehemently agree. Orphaned blocks are indeed rare in Bitcoin, because they have ten-minute block times. GHOST only helps when block times are so short that you get lots of orphaned blocks. And that's how Ethereum gets away with 15-second blocks.
- codexon 7y agoBut you haven't proven that 1 ETH 15 second block is equal or even in the same ballpark in security to a 10 minute BTC block.