<oembed><type>rich</type><version>1.0</version><author_name>npub10tqt6wdc2neye0cxwyphtre6n5uccgur94khtqjdry9wxhrvywlq6w9uu9</author_name><author_url>https://nostr.ae/npub10tqt6wdc2neye0cxwyphtre6n5uccgur94khtqjdry9wxhrvywlq6w9uu9</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2017-05-22&#xA;📝 Original message:Charlie, I&#39;ll be mostly in the tech track, of course. And I&#39;ve already&#xA;planned to meet RSK guys after their event tomorrow.&#xA;&#xA;Ryan, the more review the better. We aren&#39;t in any direct rush, other than&#xA;the natural desire to have cool things as early as possible.&#xA;&#xA;Peter, responses below:&#xA;&#xA;On May 22, 2017 9:33 AM, &#34;Peter Todd&#34; &lt;pete at petertodd.org&gt; wrote:&#xA;&#xA;On Mon, May 22, 2017 at 02:17:07AM -0400, Paul Sztorc via bitcoin-dev wrote:&#xA;&gt; This work includes the relatively new concept of &#34;Blind Merged Mining&#34;&#xA;&gt; [2] which I developed in January to allow SHA256^2 miners to merge-mine&#xA;&gt; these &#34;drivechains&#34;, even if these miners aren&#39;t running the actual&#xA;&gt; sidechain software. The goal is to prevent sidechains from affecting the&#xA;&gt; levelness of the mining &#34;playing field&#34;. BMM is conceptually similar to&#xA;&gt; ZooKeeV [3] which Peter Todd sketched out in mid-2013. BMM is not&#xA;&gt; required for drivechain, but it would address some of the last remaining&#xA;&gt; concerns.&#xA;&#xA;Thanks for the credit, although I think the security properties of what&#xA;you&#39;re&#xA;proposing are very different - and much weaker - than what I proposed in&#xA;Zookeyv.&#xA;&#xA;&#xA;As you state in [2] &#34;if miners never validate sidechains at all, whoever&#xA;bids&#xA;the most for the chain (on a continuous basis), can spam a 3-month long&#xA;stream&#xA;of invalid headers, and then withdraw all of the coins deposited to the&#xA;sidechain.&#34; and &#34;Since the mining is blind, and the sidechain-withdrawal&#xA;security-level is SPV, miners who remain blind forever have no way of&#xA;telling&#xA;who “should” really get the funds.&#34;&#xA;&#xA;Finally, you suggest that in this event, miners *do* have to upgrade to a&#xA;full&#xA;node, an expensive and time-consuming operation (and one that may be&#xA;impossible&#xA;for some miners if necessary data isn&#39;t available).&#xA;&#xA;&#xA;Surprisingly, this requirement (or, more precisely, this incentive) does&#xA;not effect miners relative to each other. The incentive to upgrade is only&#xA;for the purpose of preventing a &#34;theft&#34; -- defined as: an improper&#xA;withdrawal from a sidechain. It is not about miner revenues or the ability&#xA;to mine generally (or conduct BMM specifically). The costs of such a theft&#xA;(decrease in market price, decrease in future transaction fee levels) would&#xA;be shared collectively by all future miners. Therefore, it would have no&#xA;effect on miners relative to each other.&#xA;&#xA;Moreover, miners have other recourse if they are unable to run the node.&#xA;They can adopt a policy of simply rejecting (&#34;downvoting&#34;) any withdrawals&#xA;that they don&#39;t understand. This would pause the withdraw process until&#xA;enough miners understand enough of what is going on to proceed with it.&#xA;&#xA;Finally, the point in dispute is a single, infrequent, true/false question.&#xA;So miners may resort to semi-trusted methods to supplement their decision.&#xA;In other words, they can just ask people they trust, if the withdrawal is&#xA;correct or not. It is up to users to decide if they are comfortable with&#xA;these risks, if/when they decide to deposit to a sidechain.&#xA;&#xA;&#xA;It&#39;s unclear to me what the incentive is for miners to do any of this. Could&#xA;you explain in more detail what that incentive is?&#xA;&#xA;&#xA;It is a matter of comparing the costs and benefits. Ignoring theft, the&#xA;costs are near-zero, and the benefits are &gt;0. Specifically, they are: a&#xA;higher BTC price and greater transaction fees. Theft is discouraged by&#xA;attempting to tie a theft to a loss of confidence in the miners, as&#xA;described in the spec/website.&#xA;In general the incentives are very similar to those of Bitcoin itself.&#xA;&#xA;Paul&#xA;&#xA;&#xA;&#xA;&gt; [2] http://www.truthcoin.info/blog/blind-merged-mining/&#xA;&gt; [3] https://s3.amazonaws.com/peter.todd/bitcoin-wizards-13-10-17.log&#xA;&#xA;--&#xA;https://petertodd.org &#39;peter&#39;[:-1]@petertodd.org&#xA;-------------- next part --------------&#xA;An HTML attachment was scrubbed...&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20170522/9bb81395/attachment.html&gt;</html></oembed>