<oembed><type>rich</type><version>1.0</version><author_name>npub1azvhdrf9fu6n0tm7yez4j6zcxcedp2ct6nrcq3z74naqs7kgpk8s5t2krq</author_name><author_url>https://nostr.ae/npub1azvhdrf9fu6n0tm7yez4j6zcxcedp2ct6nrcq3z74naqs7kgpk8s5t2krq</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2015-08-29&#xA;📝 Original message:In principle I am sympathetic to dynamic block size proposals...but in&#xA;practice it seems we&#39;re barking up the wrong tree. Without mechanisms for&#xA;incentivizing validators...and checks and balances between the interests of&#xA;regular users (who want to reduce fees and confirmation time), miners (who&#xA;want to balance hashing and propagation time costs with revenue), and&#xA;validator nodes (who currrently lack any direct incentives), I think we&#39;re&#xA;talking about significant protocol complications with potential benefits&#xA;that are hard to model at best.&#xA;&#xA;On Sat, Aug 29, 2015, 3:16 AM Btc Drak via bitcoin-dev &lt;&#xA;bitcoin-dev at lists.linuxfoundation.org&gt; wrote:&#xA;&#xA;&gt; On Sat, Aug 29, 2015 at 1:29 AM, Mark Friedenbach via bitcoin-dev&#xA;&gt; &lt;bitcoin-dev at lists.linuxfoundation.org&gt; wrote:&#xA;&gt; &gt; Ah, then my mistake. It seemed so similar to an idea that was proposed&#xA;&gt; &gt; before on this mailing list:&#xA;&gt; &gt;&#xA;&gt; &gt;&#xA;&gt; http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-May/008033.html&#xA;&gt; &gt;&#xA;&gt; &gt; that my mind just filled in the gaps. I concur -- having miners -- or any&#xA;&gt; &gt; group -- vote on block size is not an intrinsically good thing. The the&#xA;&gt; &gt; original proposal due to Greg Maxwell et al was not a mechanism for&#xA;&gt; &#34;voting&#34;&#xA;&gt; &gt; but rather a feedback control that made the maximum block size that which&#xA;&gt; &gt; generated the most fees.&#xA;&gt;&#xA;&gt; Mark and Jorge,&#xA;&gt;&#xA;&gt; I am very glad you have brought up this particular objection because&#xA;&gt; it&#39;s something I thought about but was unclear if it was an opinion&#xA;&gt; that would be shared by others. I chose to omit it from the proposal&#xA;&gt; to see if it would come up during peer review.&#xA;&gt;&#xA;&gt; I feel that giving miners a blank cheque to increase blocksize, by any&#xA;&gt; means, goes against a key design of bitcoin&#39;s security model. Full&#xA;&gt; nodes keep miners honest by ensuring by validating their blocks. Under&#xA;&gt; any voting-only scheme there is no way for full nodes to keep miners&#xA;&gt; in cheque because miner have free reign to increase the blocksize.&#xA;&gt;&#xA;&gt; This problem can be solved by introducing a hard cap on blocksize. By&#xA;&gt; introducing an upper limit miners now have the freedom to increase&#xA;&gt; blocksize but only within defined parameters.  Remember my proposal&#xA;&gt; allows blocksize to increase and decrease in such a way that miners&#xA;&gt; must collectively agree if they want the size to increase.&#xA;&gt;&#xA;&gt; I believe the idea of a hard upper limit has become rather politicised&#xA;&gt; but is essential to the security model of bitcoin.&#xA;&gt;&#xA;&gt; With respect to the flexicap idea where miners can create a larger&#xA;&gt; block by paying extra difficulty, I believe that proposal has a&#xA;&gt; critical flaw because, as Gavin pointed out, it makes it very&#xA;&gt; expensive (and risky) to include a few extra transactions. I believe&#xA;&gt; it suffers from tragedy of the commons because there is no incentive&#xA;&gt; for the mining community to reach consensus. Each and every block is&#xA;&gt; going to be a gamble, &#34;should we include a few extra transactions at&#xA;&gt; the risk of losing the block?&#34;. Under my proposal miners can&#xA;&gt; collectively agree to change the blocksize. Let&#39;s say they want a 10%&#xA;&gt; increase, they can collude together to make that increase and once&#xA;&gt; reached, it remains until they want to change it again. Yet, the upper&#xA;&gt; hard limit keeps the ultimate control of the maximum block size&#xA;&gt; squarely in the hands of full nodes.&#xA;&gt;&#xA;&gt; Whilst the exact number may be up for discussion, I would propose an&#xA;&gt; initial upper limit of 8MB, so under my proposal the blocksize would&#xA;&gt; be flexible between 1MB and 8MB.&#xA;&gt;&#xA;&gt; An alternative methodology to voting in the coinbase would be to&#xA;&gt; change the vote to be the blocksize itself&#xA;&gt;&#xA;&gt; 1. miners pay extra difficulty to create a larger block.&#xA;&gt; 2. every 2016 blocks the average or median of the last 2016 blocks is&#xA;&gt; calculated and becomes the new maximum blocksize limit.&#xA;&gt;&#xA;&gt; This would retain incentive to collude to increase blocksize, as well&#xA;&gt; as the property of costing to increase while being free to propose&#xA;&gt; decrease.&#xA;&gt;&#xA;&gt; It would still require an upper blocksize limit in order for full&#xA;&gt; nodes to retain control. Without an upper limit, any proposal is going&#xA;&gt; to break the security model as full nodes give up some oversight&#xA;&gt; control over miners.&#xA;&gt;&#xA;&gt; Another way of looking at these ideas is we&#39;re raising blocksize hard&#xA;&gt; limit (to 8MB or whatever is decided), but making a soft of &#34;softer&#34;&#xA;&gt; or inner limit part of consensus. Such a concept is not really&#xA;&gt; departing from the current idea of a soft limit except to make it&#xA;&gt; consensus enforced. Obviously it&#39;s not identical, but I think you can&#xA;&gt; see the similarities.&#xA;&gt;&#xA;&gt; Does that make sense?&#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/20150829/ec6361bf/attachment-0001.html&gt;</html></oembed>