RBF Pinning with Counterparties and Competing Interest



Summary:

In a recent email thread on the bitcoin-dev mailing list, David A. Harding clarified his previous statement about a hypothetical attack on the Lightning Network. He corrected himself, stating that the attacker would be broadcasting the latest state and not a particular state. In this case, the honest counterparty would only need to send one blind child. However, the blind child will only be relayed by a Bitcoin peer if the peer also has the parent transaction. If it has the parent transaction, the user can retrieve the preimage using `getdata('tx',$txid)` and immediately resolve the HTLC with the upstream channel. Harding concludes that the strongman argument for the attack would be that the attacker could perform a targeted relay of the low-feerate preimage-containing transaction to just miners. This means that everyone else on the network would receive the honest user's higher-feerate expired-timelock transaction. Unless the honest user has a connection to a miner's node, they will neither be able to CPFP fee bump nor use `getdata` to retrieve the preimage. He apologizes for any confusion caused by his earlier statement.


Updated on: 2023-06-14T00:33:47.967921+00:00