{"type":"rich","version":"1.0","title":"Robert Spigler [ARCHIVE] wrote","author_name":"Robert Spigler [ARCHIVE] (npub1jv…n4h4q)","author_url":"https://yabu.me/npub1jvdxs20huh95a9c3870fexu3t9l75ewathejfupw26r7n3uh847shn4h4q","provider_name":"njump","provider_url":"https://yabu.me","html":"📅 Original date posted:2021-03-15\n📝 Original message:I agree with Matt.\n\nThe naked pubkey is required for some of the benefits being implemented (snicker coinjoins).\n\nEven 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't be a reason to NACK taproot.\n\n\nPersonal Fingerprint:  BF0D 3C08 A439 5AC6 11C1 5395 B70B 4A77 F850 548F\n\n\n‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐\nOn Monday, March 15, 2021 6:05 PM, Matt Corallo via bitcoin-dev \u003cbitcoin-dev at lists.linuxfoundation.org\u003e wrote:\n\n\u003e There have been many threads on this before, I'm not sure anything new has been brought up here.\n\u003e\n\u003e Matt\n\u003e\n\u003e On 3/15/21 17:48, Luke Dashjr via bitcoin-dev wrote:\n\u003e\n\u003e \u003e I do not personally see this as a reason to NACK Taproot, but it has become\n\u003e \u003e clear to me over the past week or so that many others are unaware of this\n\u003e \u003e tradeoff, so I am sharing it here to ensure the wider community is aware of\n\u003e \u003e it and can make their own judgements.\n\u003e\n\u003e Note that this is most definitelynot news to this list, eg, Anthony brought it up in \"Schnorr and taproot (etc)\n\u003e upgrade\" and there was a whole thread on it in \"Taproot: Privacy preserving switchable scripting\". This issue has been\n\u003e beaten to death, I'm not sure why we need to keep hitting the poor horse corpse.\n\u003e\n\u003e \u003e In short, Taproot loses an important safety protection against quantum.\n\u003e \u003e Note that in all circumstances, Bitcoin is endangered when QC becomes a\n\u003e \u003e reality, but pre-Taproot, it is possible for the network to \"pause\" while a\n\u003e \u003e full quantum-safe fix is developed, and then resume transacting. With Taproot\n\u003e \u003e as-is, it could very well become an unrecoverable situation if QC go online\n\u003e \u003e prior to having a full quantum-safe solution.\n\u003e\n\u003e This has been discussed ad nauseam, and it all seems to fall apart once its noted just how much Bitcoin could be stolen\n\u003e by any QC-wielding attacker due to address reuse. Ultimately, no \"pause\" can solve this issue, and, if we learned about\n\u003e a QC attacker overnight (instead of slowly over time), there isn't anything that a non-Taproot Bitcoin could do that a\n\u003e Taproot Bitcoin couldn't.\n\u003e\n\u003e \u003e Also, what I didn't know myself until today, is that we do not actually gain\n\u003e \u003e anything from this: the features proposed to make use of the raw keys being\n\u003e \u003e public prior to spending can be implemented with hashed keys as well.\n\u003e \u003e It would use significantly more CPU time and bandwidth (between private\n\u003e \u003e parties, not on-chain), but there should be no shortage of that for anyone\n\u003e \u003e running a full node (indeed, CPU time is freed up by Taproot!); at worst, it\n\u003e \u003e would create an incentive for more people to use their own full node, which\n\u003e \u003e is a good thing!\n\u003e\n\u003e This is untrue. The storage space required for Taproot transactions is materially reduced by avoiding the hash indirection.\n\u003e\n\u003e \u003e Despite this, I still don't think it's a reason to NACK Taproot: it should be\n\u003e \u003e fairly trivial to add a hash on top in an additional softfork and fix this.\n\u003e\n\u003e For the reason stated above, i think such a fork is unlikely.\n\u003e\n\u003e \u003e In addition to the points made by Mark, I also want to add two more, in\n\u003e \u003e response to Pieter's \"you can't claim much security if 37% of the supply is\n\u003e \u003e at risk\" argument. This argument is based in part on the fact that many\n\u003e \u003e people reuse Bitcoin invoice addresses.\n\u003e \u003e First, so long as we have hash-based addresses as a best practice, we can\n\u003e \u003e continue to shrink the percentage of bitcoins affected through social efforts\n\u003e \u003e discouraging address use. If the standard loses the hash, the situation\n\u003e \u003e cannot be improved, and will indeed only get worse.\n\u003e\n\u003e I truly wish this were the case, but we've been beating that drum for at least nine years and still haven't solved it.\n\u003e Worse, there's a lot of old coins that are unlikely to move any time soon that are exposed whether we like it or not.\n\u003e\n\u003e \u003e Second, when/if quantum does compromise these coins, so long as they are\n\u003e \u003e neglected or abandoned/lost coins (inherent in the current model), it can be\n\u003e \u003e seen as equivalent to Bitcoin mining. At the end of the day, 37% of supply\n\u003e \u003e minable by QCs is really no different than 37% minable by ASICs. (We've seen\n\u003e \u003e far higher %s available for mining obviously.)\n\u003e\n\u003e Except its not? One entity would be able to steal that entire block of supply rather quickly (presumably over the course\n\u003e of a few days, at maximum), instead of a slow process with significant upfront real-world cost in the form of electricity.\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"}