Published on: 2017-09-26T22:38:59+00:00
ZmnSCPxj's proposed sidechain scheme aims to give the economic majority control of sidechains without relying on miners as representatives. This proposal claims to have improved features compared to drivechains, making it even harder for a 51% mainchain miner to steal funds. According to ZmnSCPxj, the proposal requires months of broadcasting intent to steal or locking funds for an entire week-long theft, thereby increasing the difficulty for a mainchain miner to execute a theft.One concern raised in the context is the possibility of the stake winner disappearing, which could halt progress on the sidechain temporarily. The stake winner is only valid for a specific mainchain block, and if they fail to publish a sidechain header on that block, the mainchain block will not contain any sidechain header. This issue could slow down the sidechain, resulting in missed opportunities for the stake winner to earn sidechain fees.Another issue discussed is the weak mitigation against a mainchain miner attack. In the proposed scheme, a mainchain miner with over 50% hashpower can block the creation of sidechain mainstake UTXOs except its own and eventually steal them at no cost. To mitigate this, a possible solution suggested is to nest mainstake outputs in p2wsh/p2sh scripts. However, there are concerns about relocking the stake with this approach.The context also mentions a hybrid approach that might work depending on the definition of "creation." If it refers only to the initial creation of the utxo and not subsequent OP_STAKEVERIFY change outputs, this strategy could prevent the lottery from including the UTXO. As a result, it would be unable to become a stake winner or publish a sidechain block header until the lock time.Furthermore, the context raises the issue of a stake winner disappearing or a miner creating the illusion of their disappearance through censorship. This scenario would result in transaction fees being lost.In summary, ZmnSCPxj's proposed sidechain scheme claims to offer improved features compared to drivechains, making it more difficult for a 51% mainchain miner to steal funds. However, there are concerns about the stake winner disappearing, weak mitigation against a mainchain miner attack, and issues with the suggested solution of nesting mainstake outputs in p2wsh/p2sh scripts. The context also highlights the need for careful consideration and evaluation of potential flaws in the proposal.
Updated on: 2023-08-01T21:54:53.725792+00:00