V3 transaction policy for anti-pinning

V3 transaction policy for anti-pinning

Original Postby rustynail

Posted on: January 9, 2024 01:41 UTC

Understanding the potential vulnerabilities in transaction handling is crucial, especially when considering the implications of fee rates and mempool dynamics on user experience and security.

The email discussion highlights a scenario where an individual, referred to as Bob, could face delays in spending his channel funds due to an attack leveraging the current fee structure of the Bitcoin network. It emphasizes that, under certain conditions, an attacker, named Mallory, could indefinitely postpone Bob's transactions by paying minimal fees—fees that are insufficient to have the transactions included in the next block. This is due to the disparity between the minimum relay fee of 22.2 satoshi per virtual byte (sat/VB) and the actual fee required for inclusion in the coming block, which stands at 30 sat/VB. The flat nature of the mempool's feerate exacerbates this issue as transactions with minimum fees are unlikely to be mined.

The concern extends to the efficiency of hash time-locked contracts (HTLCs), which do not occupy significantly more space compared to regular outputs. Questions arise regarding the computations Peter has conducted, suggesting they would remain largely unchanged even when applied to HTLC scenarios. Furthermore, this vulnerability appears to affect HTLC transactions similarly, implying that the same type of attack could be perpetrated on them.

There is also a mention of "V3 transactions," hinting at developments or updates related to HTLCs. Queries are raised about how these V3 transactions will integrate with HTLC mechanisms, inquiring specifically about whether there will be corresponding V3 HTLC-success and HTLC-failure transactions. The email tags a user, presumably for expertise or clarification on this matter, indicating ongoing discussions and development efforts aimed at addressing these concerns within the cryptocurrency community.