Author: Peter Todd 2015-09-28 15:05:43
Published on: 2015-09-28T15:05:43+00:00
Mike Hearn and Peter Todd discuss the risks of miners building invalid blocks on top of the best work chain, instead of an ignored lower work side chain. This opens users to payment fraud. With a hard fork, all the blocks by miners that aren't checking all the rules anymore get neatly collected together on a side chain after the split, and wallets all know how to ignore that chain. In the case of a soft-fork, e.g. the IsSuperMajority() mechanism, ignoring the invalid chain is easy as well: use nVersion to detect invalid blocks when you know what soft-forks are coming up, and if presented with an unknown - but advertised - soft-fork at minimum loudly warn the user. Miners can choose to create invalid blocks, thus attacking SPV wallets; my statement with regard to pull-req #5000 comes from a risk-based approach, knowing that every invalid block is expensive and the new concern created by a soft-fork is whether or not miners will create them accidentally; miners can always create invalid blocks deliberately.
Updated on: 2023-06-10T23:17:49.445742+00:00