Author: Paul Sztorc 2017-05-24 13:43:49
Published on: 2017-05-24T13:43:49+00:00
The purpose of OP_BRIBE is to facilitate collaboration between a participant of a sidechain, Sam, and a miner of the mainchain, Mary. Sam pays Mary a predetermined amount of BTC if Mary can ensure that Sam's sidechain block becomes part of the largest chain. The longest chain in this case refers to the sidechain. Meanwhile, OP_RETURN offers some assurance that it will make it to the longest mainchain, but anything not in the longest mainchain gets discarded by everyone.To address this issue, a new construction called "SPV squared" requires the mainchain to track a minimal amount of things. In addition to a list of commitments, the mainchain also keeps track of the block number of recent sidechain blocks for the last 65,536 mainchain blocks. The schedule for side-to-main withdrawals is predictable and defined per sidechain.Disinterested mainchain miners require a single bit of information (per sidechain), which is "distress=true," indicating they should temporarily stop ACKing withdrawals from the sidechain. Drivechain handles sidechain reorgs while keeping Bitcoin miners blinded. Mainchain miners do need to maintain some data about the sidechains, but this is very minimal and does not include transaction data or arbitrary messages of the sidechain.The discussion centers around the implementation of drivechain and how it necessitates a soft fork to add a new sidechain. The mechanism is enforced by the drivechain itself, not OP_BRIBE. Miners are likely to self-impose a limit on nodes and each other to maximize their total revenues. They will eventually be required to do so. Blockstream's zk-SNARKs could enable launching a new sidechain without any modification to Core code. However, unrestrained smart contract execution might destabilize Bitcoin itself. As such, the proposal suggests reducing the size of the datacenter by removing surge suppressors and UPS's to avoid some definition of "datacenter is a room with >$XXX of equipment". Miners can soft fork in a sidechain that they have no intention of merged mining or BMMing, and the other 90% hashpower has no inherent reason not to allow that the experiment be run.
Updated on: 2023-05-20T02:34:09.357085+00:00