Hi Richard, > Sounds good to me. Although from an activation perspective it may not be > either/or, both proposals do compete for scarce reviewer time
Yes, of course. Let's say i was more interested in knowing if people who oppose CTV would oppose SIGHASH_ANYPREVOUT too. I think talking about activation of anything at this point is premature. > For someone not as versed in CTV, why is it necessary that ANYONECANPAY be > optional to emulate CTV? Is there a write-up that explains how APO-AS w/out ANYONECANPAY approximates CTV? I'm not aware of any specific to CTV. It's just that the fields covered in the CTV hash are very close to what ANYPREVOUT_ANYSCRIPT's signature hash covers [0]. The two things that CTV commits to that APO_AS does not are the number of inputs and the hash of the inputs' sequences [1]. Not committing to the number of inputs and other inputs' data is today's behaviour of ANYONECANPAY that can be combined with other signature hash types [1]. Thus APO_AS makes ACP mandatory, and to emulate CTV completely it should be optional. Antoine [0] https://github.com/bitcoin/bips/blob/master/bip-0119.mediawiki#Detailed_Specification [1] https://github.com/bitcoin/bips/blob/master/bip-0118.mediawiki#signature-message [2] https://github.com/bitcoin/bitcoin/blob/10a626a1d6776447525f50d3e1a97b3c5bbad7d6/src/script/interpreter.cpp#L1327, https://github.com/bitcoin/bitcoin/blob/10a626a1d6776447525f50d3e1a97b3c5bbad7d6/src/script/interpreter.cpp#L1517-L1522 ------- Original Message ------- Le dimanche 24 avril 2022 à 10:41 PM, Richard Myers <remy...@yakshaver.org> a écrit : > Hi darosior, > > Thanks for sharing your thoughts on this. > > > I would like to know people's sentiment about doing (a very slightly > > tweaked version of) BIP118 in place of > > (or before doing) BIP119. > > > Sounds good to me. Although from an activation perspective it may not be > either/or, both proposals do compete for scarce reviewer time so their > ordering will necessarily be driven by reviewer's priorities. My priority is > eltoo which is why I focus on BIP-118. > > > SIGHASH_ANYPREVOUTANYSCRIPT, if its "ANYONECANPAY" behaviour is made > > optional [0], can emulate CTV just fine. > > > For someone not as versed in CTV, why is it necessary that ANYONECANPAY be > optional to emulate CTV? Is there a write-up that explains how APO-AS w/out > ANYONECANPAY approximates CTV? > > In the case of eltoo commit txs, we use bring-your-own-fee (BYOF) to > late-bind fees; that means ANYONECANPAY will always be paired with APO-AS for > eltoo. Settlement txs in eltoo use just APO and do not necessarily need to be > paired with ANYONECANPAY. > > I would guess making ANYONECANPAY the default for APO-AS was a way to squeeze > in one more sighash flag. Perhaps there's another way to do it? > > Including SIGHASH_GROUP with APO for eltoo is also tempting. Specifically so > the counter-party who commits a settlement tx can use for fees their settled > to_self balance. How to rejigger the sighash flags to accommodate both APO > and GROUP may be worth some discussion. > > The BIP-118 proposal will certainly benefit from having input from reviewers > looking at other protocols than eltoo. > > -- Richard _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
