Author: Mike Kelly 2020-02-08 08:11:17
Published on: 2020-02-08T08:11:17+00:00
The discussion revolves around a form of sabotage attack called Purge attack, in which the attacker replaces the most recent blocks full of transactions with empty blocks, allowing previously confirmed transactions to return into the mempool. Users can then opportunistically double-spend their transactions back to themselves. The attack is intended to disrupt the coordination process among users in response to the attack, giving some users a chance to benefit from it and making it harder to come to consensus on how to deal with the attack. The attack itself is better classified as a form of sabotage than censorship since the goal is to demonstrate the ongoing mutability of transactions beyond any inherent heuristic for "finality", damaging the network's future ability to offer settlement assurances. Nodes may reject announced blocks that include transactions that are in contest with any in their mempool or contest pool, violating the principle of Blockchain Self-Containment, i.e., consensus rules can only check what is in the blockchain. Purge attacks can still be defended against without requiring mass cooperation. With enough self-interested users, the fee offered to confirm the transactions can be substantial enough that non-censoring miners can be convinced to mine those transactions. The increased mining fees for the transactions being censored is an economic counterattack on the censoring miner, forgoing the mining fees. The author has been trying to eliminate transaction replacement that is consensus compatible, and the best he could come up with is "Uncontested Safe," which he tried to sketch out in a brief medium article. Feedback would be appreciated.
Updated on: 2023-06-13T23:22:25.703665+00:00