Combined summary - Ephemeral Anchors and MEVil
The discussion focuses on the economic incentives and cost-benefit analysis associated with blockchain transaction strategies, specifically examining the advantages of manipulating transactions for economic gain.
It details a scenario where controlling a transaction (
TxB) becomes economically beneficial by paying 1,780 satoshis more than a base cost to evict another transaction (
TxC), in contrast to other strategies requiring payments over 10,000 satoshis. This highlights a preference for strategies that save costs while increasing the value of the transaction anchor.
The conversation proposes a method to manage transaction outputs and fees efficiently through transactions with zero-value outputs and anyone-can-spend outputs that are time-locked far into the future. This aims to simplify the transaction process and keep commitment transaction fees at zero without affecting mempool operations. The importance of accurately simulating transaction conflicts using Replace-by-Fee (RBF) logic after clustering in the mempool is emphasized to optimize transaction management.
There are concerns over the manipulation of ephemeral anchor values and its impact on transaction fees, revealing a potential vulnerability where strategic manipulation by third parties could force channel parties to incur higher fees. The dialogue suggests finding an equilibrium in fee rates and adjusting the process to be more incentive-compatible for miners.
Technical discussions cover calculating transaction fee rates, especially comparing combined transactions versus single transactions involving the burn of an ephemeral anchor. The interaction with pending mempool transactions and its effect on diagram checks' effectiveness is questioned. Suggestions include optimizing the byte count for burns and adjusting protocol rules to align with miner behaviors and incentives.
An overview of implementing a transaction fee structure with ephemeral anchor outputs is provided, using diagrams to illustrate different scenarios and outcomes according to the proposed fee structure. The complexity of transaction fee economics and strategic considerations for making transactions attractive to miners within a competitive environment is discussed. An anomaly in the "anti-MEVil" mechanism designed to mitigate malicious transaction ordering is highlighted, showing how increased ephemeral anchor values can affect transaction dynamics.
Lastly, the recent anomaly in transaction processing is attributed to the implementation of anti-Denial of Service (DoS) rules, which inadvertently introduce a loophole exploitable by adversaries. Specifically, manipulating the ephemeral anchor value becomes advantageous for causing conflicts between child transactions, exemplified by the conflict between
TxD. This situation necessitates a review and potential modification of existing anti-DoS measures to prevent exploitation.