CSFS Re-Keying and Laddering, Deterministic Update Rekeying, & Applications to LN-Symmetry

This is a collab post with Rearden . At Bitcoin++ in Austin this year Rearden showed that there are many ways to realize Lightning Symmetry using various bitcoin upgrade proposals. All of these methods require either an extra signing round-trip for each channel update, or the ability to force the hash of the settlement transaction to be visible with its corresponding update transaction. This can…