Scaling Lightning Safely With Feerate-Dependent Timelocks

Scaling Lightning Safely With Feerate-Dependent Timelocks

Posted on: December 28, 2023 18:06 UTC

The email from John provides insights into the functioning and security considerations of Forward Deployable Transactions (FDTs).

FDTs do not operate based on the most recent window; instead, they depend on the existence of an aligned window between when a child transaction's absolute and relative timelocks are satisfied and the occurrence of the current block. This alignment is crucial as it enables the establishment of tighter security bounds within a specific time frame.

John further illustrates this concept by explaining that two consecutive aligned 64-block windows present dishonest miners with only two opportunities to generate artificial aligned low-feerate windows. In contrast, if alignment were not a requisite, they would have 65 such opportunities. The implication here is that the necessity for alignment significantly reduces the chances for dishonest behavior. Moreover, the flexibility to adjust the window size offers a balance between latency and security, suggesting that one can optimize for quicker transaction times or increased security depending on the situation.

John agrees with Boris's idea, which indicates a collaborative approach to their discussion, although the specifics of Boris's suggestion are not detailed in the provided excerpt. The overall tone of the message reflects an agreement on enhancing the mechanism under discussion, presumably to make FDTs more secure and efficient.