<oembed><type>rich</type><version>1.0</version><author_name>npub1dpdfw74plzm03mzglkdegp3hqn6qs9yffqefa5kh98mru49nrg7szymz3t</author_name><author_url>https://nostr.ae/npub1dpdfw74plzm03mzglkdegp3hqn6qs9yffqefa5kh98mru49nrg7szymz3t</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2022-02-11&#xA;📝 Original message:I don&#39;t oppose recursive covenants per se, but in prior posts I have&#xA;expressed uncertainty about proposals that enable more &#34;featureful&#34;&#xA;covenants by adding more kinds of computation into bitcoin script.&#xA;&#xA;Not that anyone here is necessarily saying otherwise, but I am very&#xA;interested in limiting operations in bitcoin script to &#34;verification&#34; (vs.&#xA;&#34;computation&#34;) to the extent practical, and instead encouraging general&#xA;computation be done off-chain. This of course isn&#39;t a new observation and I&#xA;think the last few years have been very successful to that effect, e.g. the&#xA;popularity of the &#34;scriptless scripts&#34; idea and Taproot&#39;s emphasis on&#xA;embedding computational artifacts in key tweaks.&#xA;&#xA;My (maybe unfounded?) worry about opcodes like OP_CAT and OP_TX is that&#xA;more logic will live in script than is necessary, and so the burden to&#xA;verify the chain may grow and the extra &#34;degrees of freedom&#34; in script may&#xA;make it harder to reason about. But I guess at this point there aren&#39;t&#xA;alternative means to construct new kinds of sighashes that are necessary&#xA;for some interesting covenants.&#xA;&#xA;One thing I like about CTV is that it buys a lot of functionality without&#xA;increasing the &#34;surface area&#34; of script&#39;s design. In general I think there&#xA;is a lot to be said for this &#34;jets&#34;-style approach[0] of codifying the&#xA;script operations that you&#39;d actually want to do into single opcodes. This&#xA;adds functionality while introducing minimal surface area to script, giving&#xA;script implementers more flexibility for, say, optimization. But of course&#xA;this comes at the cost of precluding experimentation, and probably&#xA;requiring more soft-forking. Though whether the place for script&#xA;experimentation using more general-purpose opcodes on the main chain is&#xA;another interesting debate...&#xA;&#xA;Sorry for going a little off-topic there.&#xA;&#xA;[0]: https://medium.com/blockstream/simplicity-jets-release-803db10fd589&#xA;&#xA;&#xA;On Thu, Feb 10, 2022 at 7:55 PM David A. Harding via bitcoin-dev &lt;&#xA;bitcoin-dev at lists.linuxfoundation.org&gt; wrote:&#xA;&#xA;&gt; On Mon, Feb 07, 2022 at 08:34:30PM -0800, Jeremy Rubin via bitcoin-dev&#xA;&gt; wrote:&#xA;&gt; &gt; Whether [recursive covenants] is an issue or not precluding this sort&#xA;&gt; &gt; of design or not, I defer to others.&#xA;&gt;&#xA;&gt; For reference, I believe the last time the merits of allowing recursive&#xA;&gt; covenants was discussed at length on this list[1], not a single person&#xA;&gt; replied to say that they were opposed to the idea.&#xA;&gt;&#xA;&gt; I would like to suggest that anyone opposed to recursive covenants speak&#xA;&gt; for themselves (if any intelligent such people exist).  Citing the risk&#xA;&gt; of recursive covenants without presenting a credible argument for the&#xA;&gt; source of that risk feels to me like (at best) stop energy[2] and (at&#xA;&gt; worst) FUD.&#xA;&gt;&#xA;&gt; -Dave&#xA;&gt;&#xA;&gt; [1]&#xA;&gt; https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2021-July/019203.html&#xA;&gt; [2]&#xA;&gt; http://radio-weblogs.com/0107584/stories/2002/05/05/stopEnergyByDaveWiner.html&#xA;&gt;     (thanks to AJ who told me about stop energy one time when I was&#xA;&gt;     producing it)&#xA;&gt;&#xA;&gt; _______________________________________________&#xA;&gt; bitcoin-dev mailing list&#xA;&gt; bitcoin-dev at lists.linuxfoundation.org&#xA;&gt; https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev&#xA;&gt;&#xA;-------------- next part --------------&#xA;An HTML attachment was scrubbed...&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20220211/bf500325/attachment.html&gt;</html></oembed>