delvingbitcoin
0conf LN channels and v3 anchors
Posted on: February 1, 2024 22:58 UTC
In the realm of cryptocurrency transactions, particularly those that involve funding, there are methods available to ensure that a transaction is confirmed promptly in case of an emergency.
One such method involves using Child Pays for Parent (CPFP), which can be executed through commitment and anchor spending. However, this approach faces challenges due to the possibility of pinning the funding transaction, which effectively jams the transaction from being confirmed.
Looking ahead, there is a potential solution that could significantly improve the security and efficiency of these transactions. By integrating a cluster mempool, enabling package relay, and adopting a v3 policy as a priority opt-in, we could see substantial mitigation against pinning risks. The proposed v3 policy would remove current limitations on ancestor restrictions and the one-child limit, allowing for more flexibility in managing unconfirmed transactions. With these changes, a funding transaction can be made with v3 protocol, and any party can utilize CPFP via the commitment + anchor spend package. Pinning risks are reduced because all descendants of the funding transaction would require a priority fee rate, making it costly and less advantageous for attackers to pin the transaction preemptively.
During the transition period to v3, maintaining the status quo might be the most practical approach. This includes adding a shared anchor to non-v3 funding transactions, which permits CPFP in urgent situations while also supporting various ancestor topologies like splice trees. Although this does not fully resolve the issue of pinning, it ensures no regression from the current state of transaction handling.
The above solutions represent significant steps forward in making cryptocurrency transactions more reliable and secure, particularly in situations that demand prompt confirmation. These proposed changes promise to reduce the risk and impact of pinning attacks, ultimately fostering a more resilient transaction environment.