On Mon, Dec 24, 2018 at 11:47:38AM +0000, ZmnSCPxj via bitcoin-dev wrote: > A boutique protocol would reduce the number of existing onchain wallets that > could be integrated in such UI.
Seems like PSBT would be a sufficient protocol: 0) lightning node generates a PSBT for a new channel, with no inputs and a single output of the 2-of-2 address 1) wallet funds the PSBT but doesn't sign it, adding a change address if necessary, and could combine with other tx's bustapay style 2) lightning determines txid from PSBT, and creates update/settlement tx's for funding tx so funds can be recovered 3) wallet signs and publishes the PSBT 4) lightning sees tx on chain and channel is open That's a bit more convoluted than "(0) lightning generates an address and value, and creates NOINPUT update/settlement tx's for that address/value; (1) wallet funds address to exactly that value; (2) lightning monitors blockchain for payment to that address" of course. But it avoids letting users get into the habit of passing NOINPUT addresses around, or the risk of a user typo'ing the value and losing money immediately, and it has the benefit that the wallet can tweak the value if (eg) that avoids a change address or enhances privacy (iirc, c-lightning tweaks payment values for that reason). If the channel's closed cooperatively, it also avoids ever needing to publish a NOINPUT sig (or NOINPUT tagged output). Does that seem a fair trade off? Cheers, aj _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev