Published on: 2021-12-16T14:12:43+00:00
The Lightning Network development team has proposed a solution to address the issue of spam via hash time-locked contracts (HTLCs). The proposal involves ascribing blame to malicious actors by using a new lightning message called "blame_channel" in combination with onion messages. This mechanism requires a fixed time for reply after negotiating an HTLC, and if the reply does not occur, the downstream peer is considered malicious. The reply time is proportional to the cltv delta of that hop, and it comes in the form of either an update_fulfill_htlc or an update_fail_htlc message. If a node cannot send these messages, it must send a blame_channel message that includes proof of setting up the HTLC with the next peer. However, there are limitations to the proposal, such as not directly preventing spam via HTLCs and the possibility of short reply intervals being an issue with Multi-Path Payments. Despite these limitations, the proposed solution offers a step towards mitigating HTLC spam and the team is seeking feedback and criticism to further develop the mechanism.Another limitation of the proposal is the potential for a malicious node to blame an honest one. This can occur when a payment goes through multiple nodes and the malicious node withholds the settlement message from the next node, causing delays and blaming the subsequent node. Additionally, constructing the blame proofs may be challenging, as they would need to include data from commitment_signed and proof of revoking the previous commitment without compromising channel security. The proposal suggests extensions and limitations to overcome these challenges.The proposed solution aims to allow several nodes on the network to identify malicious or slow actors and take preventive measures, especially if they have direct channels with the suspected peer. Furthermore, once stuckless payments are available, an honest sender can quickly discard a stuck HTLC and try another path without involving the malicious node. The author acknowledges that the proposal may not be entirely secure but believes it is a step towards mitigating abuse of onion routing and HTLCs spam. The proposal concludes with a request for review and criticism from the community.
Updated on: 2023-07-31T23:57:47.143029+00:00