<oembed><type>rich</type><version>1.0</version><title>Robert Spigler [ARCHIVE] wrote</title><author_name>Robert Spigler [ARCHIVE] (npub1jv…n4h4q)</author_name><author_url>https://yabu.me/npub1jvdxs20huh95a9c3870fexu3t9l75ewathejfupw26r7n3uh847shn4h4q</author_url><provider_name>njump</provider_name><provider_url>https://yabu.me</provider_url><html>📅 Original date posted:2021-03-15&#xA;📝 Original message:I agree with Matt.&#xA;&#xA;The naked pubkey is required for some of the benefits being implemented (snicker coinjoins).&#xA;&#xA;Even with pubkey hashes, bitcoin could still be stolen because the pubkey is published on spend.  Regardless, QC needs to be fixed later on (decades), and shouldn&#39;t be a reason to NACK taproot.&#xA;&#xA;&#xA;Personal Fingerprint:  BF0D 3C08 A439 5AC6 11C1 5395 B70B 4A77 F850 548F&#xA;&#xA;&#xA;‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐&#xA;On Monday, March 15, 2021 6:05 PM, Matt Corallo via bitcoin-dev &lt;bitcoin-dev at lists.linuxfoundation.org&gt; wrote:&#xA;&#xA;&gt; There have been many threads on this before, I&#39;m not sure anything new has been brought up here.&#xA;&gt;&#xA;&gt; Matt&#xA;&gt;&#xA;&gt; On 3/15/21 17:48, Luke Dashjr via bitcoin-dev wrote:&#xA;&gt;&#xA;&gt; &gt; I do not personally see this as a reason to NACK Taproot, but it has become&#xA;&gt; &gt; clear to me over the past week or so that many others are unaware of this&#xA;&gt; &gt; tradeoff, so I am sharing it here to ensure the wider community is aware of&#xA;&gt; &gt; it and can make their own judgements.&#xA;&gt;&#xA;&gt; Note that this is most definitelynot news to this list, eg, Anthony brought it up in &#34;Schnorr and taproot (etc)&#xA;&gt; upgrade&#34; and there was a whole thread on it in &#34;Taproot: Privacy preserving switchable scripting&#34;. This issue has been&#xA;&gt; beaten to death, I&#39;m not sure why we need to keep hitting the poor horse corpse.&#xA;&gt;&#xA;&gt; &gt; In short, Taproot loses an important safety protection against quantum.&#xA;&gt; &gt; Note that in all circumstances, Bitcoin is endangered when QC becomes a&#xA;&gt; &gt; reality, but pre-Taproot, it is possible for the network to &#34;pause&#34; while a&#xA;&gt; &gt; full quantum-safe fix is developed, and then resume transacting. With Taproot&#xA;&gt; &gt; as-is, it could very well become an unrecoverable situation if QC go online&#xA;&gt; &gt; prior to having a full quantum-safe solution.&#xA;&gt;&#xA;&gt; This has been discussed ad nauseam, and it all seems to fall apart once its noted just how much Bitcoin could be stolen&#xA;&gt; by any QC-wielding attacker due to address reuse. Ultimately, no &#34;pause&#34; can solve this issue, and, if we learned about&#xA;&gt; a QC attacker overnight (instead of slowly over time), there isn&#39;t anything that a non-Taproot Bitcoin could do that a&#xA;&gt; Taproot Bitcoin couldn&#39;t.&#xA;&gt;&#xA;&gt; &gt; Also, what I didn&#39;t know myself until today, is that we do not actually gain&#xA;&gt; &gt; anything from this: the features proposed to make use of the raw keys being&#xA;&gt; &gt; public prior to spending can be implemented with hashed keys as well.&#xA;&gt; &gt; It would use significantly more CPU time and bandwidth (between private&#xA;&gt; &gt; parties, not on-chain), but there should be no shortage of that for anyone&#xA;&gt; &gt; running a full node (indeed, CPU time is freed up by Taproot!); at worst, it&#xA;&gt; &gt; would create an incentive for more people to use their own full node, which&#xA;&gt; &gt; is a good thing!&#xA;&gt;&#xA;&gt; This is untrue. The storage space required for Taproot transactions is materially reduced by avoiding the hash indirection.&#xA;&gt;&#xA;&gt; &gt; Despite this, I still don&#39;t think it&#39;s a reason to NACK Taproot: it should be&#xA;&gt; &gt; fairly trivial to add a hash on top in an additional softfork and fix this.&#xA;&gt;&#xA;&gt; For the reason stated above, i think such a fork is unlikely.&#xA;&gt;&#xA;&gt; &gt; In addition to the points made by Mark, I also want to add two more, in&#xA;&gt; &gt; response to Pieter&#39;s &#34;you can&#39;t claim much security if 37% of the supply is&#xA;&gt; &gt; at risk&#34; argument. This argument is based in part on the fact that many&#xA;&gt; &gt; people reuse Bitcoin invoice addresses.&#xA;&gt; &gt; First, so long as we have hash-based addresses as a best practice, we can&#xA;&gt; &gt; continue to shrink the percentage of bitcoins affected through social efforts&#xA;&gt; &gt; discouraging address use. If the standard loses the hash, the situation&#xA;&gt; &gt; cannot be improved, and will indeed only get worse.&#xA;&gt;&#xA;&gt; I truly wish this were the case, but we&#39;ve been beating that drum for at least nine years and still haven&#39;t solved it.&#xA;&gt; Worse, there&#39;s a lot of old coins that are unlikely to move any time soon that are exposed whether we like it or not.&#xA;&gt;&#xA;&gt; &gt; Second, when/if quantum does compromise these coins, so long as they are&#xA;&gt; &gt; neglected or abandoned/lost coins (inherent in the current model), it can be&#xA;&gt; &gt; seen as equivalent to Bitcoin mining. At the end of the day, 37% of supply&#xA;&gt; &gt; minable by QCs is really no different than 37% minable by ASICs. (We&#39;ve seen&#xA;&gt; &gt; far higher %s available for mining obviously.)&#xA;&gt;&#xA;&gt; Except its not? One entity would be able to steal that entire block of supply rather quickly (presumably over the course&#xA;&gt; of a few days, at maximum), instead of a slow process with significant upfront real-world cost in the form of electricity.&#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</html></oembed>