Author: Matt Corallo 2015-10-28 02:08:52
Published on: 2015-10-28T02:08:52+00:00
On October 14, 2015, a conversation took place regarding the use of microblocks in Bitcoin. Matt Corallo brought up an issue where there is no way to punish people if there is a double spend in a microblock that happens in key block which reorg'd away the first transaction. Ittay responded by saying that such forks should occur almost every key-block publication and that a user should wait before accepting a transaction to make sure there was no key-block missed. The attacker does not need to withold their keyblock at all but can set their hashpower to start mining a keyblock immediately prior to this microblock.The confirmation time for microblocks possibly doesn't need to be a full key-block, but it needs to be a reasonable period after which such an attacker would lose more in fees than the value of their double-spend. This game theory starts to get rather complicated and it doesn't suggest accepting microblocks as confirmations is safe. Greg Slepak brought up a good point on Twitter that users could no longer pick transactions in a mining pool which was set up in such a way (it could be tweaked to do so with separate rewards and pubkeys, but now the user can commit fraud at a much lower cost - their own pool reward, not the block's total reward).Fraud proof removes all the attacker's revenue. It's like the attacker sacrifices an entire block for double spending in the current system.
Updated on: 2023-05-19T22:13:32.172853+00:00