{"type":"rich","version":"1.0","author_name":"npub1xqcwcttsyk0a64d63crrwsxp88pa42np37rw87hrfn4uku78g2aqltcnns","author_url":"https://nostr.ae/npub1xqcwcttsyk0a64d63crrwsxp88pa42np37rw87hrfn4uku78g2aqltcnns","provider_name":"njump","provider_url":"https://nostr.ae","html":"📅 Original date posted:2022-02-12\n📝 Original message:\u003e in the case of a multisig/non-consensus based system, exit from that\nrestriction is still possible\n\nBut why do we care if someone reduces the value of coins they own by\npermanently encumbering them in some way? Burning coins permanently\nencumbers them so much they can't be spent at all. If the worry is\ndepleting the supply of sats, don't worry, the amount of value lost by\nthose encumbered is gained but the rest of the coins. Just like burning,\nencumbering your coins in a way that devalues them is a donation to the\nrest of us.\n\nCould you clarify what harm there is to those who choose not to accept such\nencumbered coins? Or are you just saying that those who do accept such\nencumbered coins may be harmed by doing so?\n\nOn Sat, Feb 12, 2022, 06:11 darosior via bitcoin-dev \u003c\nbitcoin-dev at lists.linuxfoundation.org\u003e wrote:\n\n\u003e Such a construct would present dangerous implications to the fungibility\n\u003e of individual UTXOs by introducing a totally different risk model in being\n\u003e paid with such a coin compared to any other coin not encumbered by such a\n\u003e condition\n\u003e\n\u003e\n\u003e How is that different from being paid in an altcoin?\n\u003e It seems to me that being able to say \"sorry, your money isn't good here\"\n\u003e is at the heart of Bitcoin's security (similarly to enforcing the network\n\u003e rules with your node). If someone can coerce you into using another\n\u003e currency, you've already lost.\n\u003e\n\u003e Now there is left the influence on the system of an user being coerced\n\u003e into using gov coin (on another chain) or an encumbered bit coin. Sure the\n\u003e latter would decrease the supply available, but that's already possible to\n\u003e do today.\n\u003e\n\u003e ------- Original Message -------\n\u003e Le vendredi 11 février 2022 à 7:12 PM, digital vagabond via bitcoin-dev \u003c\n\u003e bitcoin-dev at lists.linuxfoundation.org\u003e a écrit :\n\u003e\n\u003e This is Shinobi (can verify out of band at @brian_trollz on Twitter, I\n\u003e only signed up to the list with this email to read initially, but feel like\n\u003e I should reply to this as I think I am one of the only people in this space\n\u003e who has voiced concerns with recursive covenants).\n\u003e\n\u003e My concerns don't really center specifically around recursion itself\n\u003e necessarily, but unbounded recursion in combination with too much\n\u003e generality/flexibility in what types of conditions future UTXOs can be\n\u003e encumbered with based on the restriction of such covenants. Forgive the\n\u003e hand waiving arguments without getting into specific opcodes, but I would\n\u003e summarize my concerns with a hypothetical construct that I believe would be\n\u003e incredibly damaging to fungibility. Imagine a covenant design that was\n\u003e flexible enough to create an encumbrance like this: a script specifies a\n\u003e specific key in a multisig controlled by some authority figure (or a branch\n\u003e in the script that would allow unilateral control by such an authority),\n\u003e and the conditions of the covenant would perpetually require than any spend\n\u003e from the covenant can only be sent to a script involving that key from said\n\u003e authority, preventing by consensus any removal of that central authorities\n\u003e involvement in control over that UTXO. Such a construct would present\n\u003e dangerous implications to the fungibility of individual UTXOs by\n\u003e introducing a totally different risk model in being paid with such a coin\n\u003e compared to any other coin not encumbered by such a condition, and also\n\u003e potentially introduce a shift in the scope of what a 51% attack could\n\u003e accomplish in terms of permanent consequences attempting to coerce coins\n\u003e into such covenants, as opposed to right now only being able to accomplish\n\u003e censorship or temporary network disruption.\n\u003e\n\u003e I know that such a walled garden could easily be constructed now with\n\u003e multisig and restrictions on where coins can be withdrawn to from exchanges\n\u003e or whatever place they initially purchased from, as is demonstrated by the\n\u003e implementation of the Asset Management Platform by Blockstream for use on\n\u003e Liquid with regulated equity tokens, but I think the important distinction\n\u003e between such non-consensus system designed to enforce such restrictions and\n\u003e a recursive covenant to accomplish the same is that in the case of a\n\u003e multisig/non-consensus based system, exit from that restriction is still\n\u003e possible under the consensus rules of the protocol. If such a construct was\n\u003e possible to build with a recursive covenant enforced by consensus, coins\n\u003e encumbered by such a covenant would literally be incapable of escaping\n\u003e those restrictions without hardforking the protocol, leaving any such UTXOs\n\u003e permanently non-fungible with ones not encumbered by such conditions.\n\u003e\n\u003e I'm not that deeply familiar with all the working pieces involved in the\n\u003e recent TXHASH + CSFS proposal, and whether such a type of overly (IMO)\n\u003e generalized recursion would be possible to construct, but one of the\n\u003e reasons CTV does not bother me in terms of such concerns is the inability\n\u003e to infinitely recurse in such a generalized way given the requirements to\n\u003e exactly specify the destination of future spends in constructing a chain of\n\u003e CTV encumbrances. I'd very much appreciate any feedback on my concerns, and\n\u003e if this side tracks the discussion I apologize, but I felt given the issue\n\u003e has been mentioned a few times in this thread it was appropriate for me to\n\u003e voice the concerns here so they could be addressed directly.\n\u003e\n\u003e On Fri, Feb 11, 2022 at 11:42 AM James O'Beirne via bitcoin-dev \u003c\n\u003e bitcoin-dev at lists.linuxfoundation.org\u003e wrote:\n\u003e\n\u003e\u003e I don't oppose recursive covenants per se, but in prior posts I have\n\u003e\u003e expressed uncertainty about proposals that enable more \"featureful\"\n\u003e\u003e covenants by adding more kinds of computation into bitcoin script.\n\u003e\u003e\n\u003e\u003e Not that anyone here is necessarily saying otherwise, but I am very\n\u003e\u003e interested in limiting operations in bitcoin script to \"verification\" (vs.\n\u003e\u003e \"computation\") to the extent practical, and instead encouraging general\n\u003e\u003e computation be done off-chain. This of course isn't a new observation and I\n\u003e\u003e think the last few years have been very successful to that effect, e.g. the\n\u003e\u003e popularity of the \"scriptless scripts\" idea and Taproot's emphasis on\n\u003e\u003e embedding computational artifacts in key tweaks.\n\u003e\u003e\n\u003e\u003e My (maybe unfounded?) worry about opcodes like OP_CAT and OP_TX is that\n\u003e\u003e more logic will live in script than is necessary, and so the burden to\n\u003e\u003e verify the chain may grow and the extra \"degrees of freedom\" in script may\n\u003e\u003e make it harder to reason about. But I guess at this point there aren't\n\u003e\u003e alternative means to construct new kinds of sighashes that are necessary\n\u003e\u003e for some interesting covenants.\n\u003e\u003e\n\u003e\u003e One thing I like about CTV is that it buys a lot of functionality without\n\u003e\u003e increasing the \"surface area\" of script's design. In general I think there\n\u003e\u003e is a lot to be said for this \"jets\"-style approach[0] of codifying the\n\u003e\u003e script operations that you'd actually want to do into single opcodes. This\n\u003e\u003e adds functionality while introducing minimal surface area to script, giving\n\u003e\u003e script implementers more flexibility for, say, optimization. But of course\n\u003e\u003e this comes at the cost of precluding experimentation, and probably\n\u003e\u003e requiring more soft-forking. Though whether the place for script\n\u003e\u003e experimentation using more general-purpose opcodes on the main chain is\n\u003e\u003e another interesting debate...\n\u003e\u003e\n\u003e\u003e Sorry for going a little off-topic there.\n\u003e\u003e\n\u003e\u003e [0]: https://medium.com/blockstream/simplicity-jets-release-803db10fd589\n\u003e\u003e\n\u003e\u003e\n\u003e\u003e On Thu, Feb 10, 2022 at 7:55 PM David A. Harding via bitcoin-dev \u003c\n\u003e\u003e bitcoin-dev at lists.linuxfoundation.org\u003e wrote:\n\u003e\u003e\n\u003e\u003e\u003e On Mon, Feb 07, 2022 at 08:34:30PM -0800, Jeremy Rubin via bitcoin-dev\n\u003e\u003e\u003e wrote:\n\u003e\u003e\u003e \u003e Whether [recursive covenants] is an issue or not precluding this sort\n\u003e\u003e\u003e \u003e of design or not, I defer to others.\n\u003e\u003e\u003e\n\u003e\u003e\u003e For reference, I believe the last time the merits of allowing recursive\n\u003e\u003e\u003e covenants was discussed at length on this list[1], not a single person\n\u003e\u003e\u003e replied to say that they were opposed to the idea.\n\u003e\u003e\u003e\n\u003e\u003e\u003e I would like to suggest that anyone opposed to recursive covenants speak\n\u003e\u003e\u003e for themselves (if any intelligent such people exist). Citing the risk\n\u003e\u003e\u003e of recursive covenants without presenting a credible argument for the\n\u003e\u003e\u003e source of that risk feels to me like (at best) stop energy[2] and (at\n\u003e\u003e\u003e worst) FUD.\n\u003e\u003e\u003e\n\u003e\u003e\u003e -Dave\n\u003e\u003e\u003e\n\u003e\u003e\u003e [1]\n\u003e\u003e\u003e https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2021-July/019203.html\n\u003e\u003e\u003e [2]\n\u003e\u003e\u003e http://radio-weblogs.com/0107584/stories/2002/05/05/stopEnergyByDaveWiner.html\n\u003e\u003e\u003e (thanks to AJ who told me about stop energy one time when I was\n\u003e\u003e\u003e producing it)\n\u003e\u003e\u003e\n\u003e\u003e\u003e _______________________________________________\n\u003e\u003e\u003e bitcoin-dev mailing list\n\u003e\u003e\u003e bitcoin-dev at lists.linuxfoundation.org\n\u003e\u003e\u003e https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev\n\u003e\u003e\u003e\n\u003e\u003e _______________________________________________\n\u003e\u003e bitcoin-dev mailing list\n\u003e\u003e bitcoin-dev at lists.linuxfoundation.org\n\u003e\u003e https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev\n\u003e\u003e\n\u003e\n\u003e _______________________________________________\n\u003e bitcoin-dev mailing list\n\u003e bitcoin-dev at lists.linuxfoundation.org\n\u003e https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev\n\u003e\n-------------- next part --------------\nAn HTML attachment was scrubbed...\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20220212/582bc544/attachment-0001.html\u003e"}