<oembed><type>rich</type><version>1.0</version><author_name>npub149tvqh6gesh22h60jrehl5clrxscx6q65wznq9ty6pae8sxq00esg5vasy</author_name><author_url>https://nostr.ae/npub149tvqh6gesh22h60jrehl5clrxscx6q65wznq9ty6pae8sxq00esg5vasy</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2017-03-30&#xA;📝 Original message:&gt; The block size itself should be set based on the amount of fees being&#xA;paid to miners to make a block.&#xA;&#xA;There&#39;s a formula to this as well, though going from that to a blocksize&#xA;number will be very difficult.  Miner fees need to be sufficient to&#xA;maintain economic protection against attackers.  There is no reason that&#xA;miner fees need to be any higher than &#34;sufficient.&#34;  I believe that&#xA;&#34;sufficient&#34; value can be estimated by considering a potential attacker&#xA;seeking to profit from short-selling Bitcoin after causing a panic crash.&#xA;If they can earn more profit from shorting Bitcoin than it costs to buy,&#xA;build/deploy, and perform a 51% attack to shut down the network, then we&#xA;are clearly vulnerable.  The equation for the profit side of the equation&#xA;can be worked out as:&#xA;&#xA;(bitcoin_price * num_coins_shortable * panic_price_drop_percentage)&#xA;&#xA;The equation for the cost side of the equation depends on the total amount&#xA;of miner hardware that the network is sustainably paying to operate,&#xA;factoring in all costs of the entire bitcoin mining lifecycle(HW cost,&#xA;deployment cost, maintenance cost, electricity, amortized facilities cost,&#xA;business overheads, orphan losses, etc) except chip design, which the&#xA;attacker may be able to take advantage of for free.  For convenience I&#39;m&#xA;simplifying that complicated cost down to a single number I&#39;m calling&#xA;&#34;hardware_lifespan&#34; although the concept is slightly more involved than&#xA;that.&#xA;&#xA;(total_miner_payouts * bitcoin_price * hardware_lifespan)&#xA;&#xA;Bitcoin_price is on boths ides of the equation and so can be divided out,&#xA;giving:&#xA;&#xA;Unsafe point = (num_coins_shortable * panic_price_drop_percentage) &lt;&#xA;(total_miner_payouts&#xA;* hardware_lifespan)&#xA;&#xA;Estimating the total number of shortable coins an attacker of nearly&#xA;unlimited funds is tricky, especially when things like high leverage levels&#xA;or naked short selling may be offered by exchanges.  The percent of damage&#xA;the resulting panic would cause is also tricky to estimate, but on both&#xA;numbers we can make some rough guesses and see how they play out.  With&#xA;more conservative numbers like say, 2 year hardware lifespan, 10% short,&#xA;70% panic drop you get: 1,300k coins profit, 1800 BTC/day in fees minimum&#xA;needed to make the attack cost more than it profits.&#xA;&#xA;Using various inputs and erring on the side of caution, I get a minimum&#xA;BTC/day fee range of 500-2000.  Unfortunately if the blocksize isn&#39;t&#xA;increased, a relatively small number of transactions/users have to bear the&#xA;full cost of the minimum fees, over time increasing the minimum &#34;safe&#34;&#xA;average fee paid to 0.008 BTC, 30x the fees people are complaining about&#xA;today, and increasing in real-world terms as price increases.  All that&#xA;said, I believe the costs for node operation are the number that gets hit&#xA;first as blocksizes are increased, at least past 2020.  I don&#39;t think&#xA;blocksizes could be increased to such a size that the insufficient-fee&#xA;vulnerability would be a bigger concern than high node operational costs.&#xA;The main thing I don&#39;t have a good grasp on at the moment is any math to&#xA;estimate how many nodes we need to protect against the attacks that can&#xA;come from having few nodes, or even a clear understanding of what those&#xA;attacks are.&#xA;&#xA;&gt; A block so big that 100% of the transactions will always be mined in the&#xA;&gt; next block will just cause a large section of people to no longer feel the&#xA;&gt; need to pay fees.&#xA;&#xA;This is also totally true.  A system that tried to eliminate the fee&#xA;markets would be flawed, and fortunately miners have significant reasons to&#xA;oppose such a system.&#xA;&#xA;The reverse is also a problem - If miners as a large group sought to lower&#xA;blocksizes to force fee markets higher, that could be a problem.  I don&#39;t&#xA;have solutions for the issue at this time, but something I&#39;ve turned over&#xA;in my mind.&#xA;&#xA;On Thu, Mar 30, 2017 at 3:30 AM, Tom Zander via bitcoin-dev &lt;&#xA;bitcoin-dev at lists.linuxfoundation.org&gt; wrote:&#xA;&#xA;&gt; On Thursday, 30 March 2017 07:23:31 CEST Ryan J Martin via bitcoin-dev&#xA;&gt; wrote:&#xA;&gt; &gt;      The original post and the assorted limit proposals---lead me to&#xA;&gt; &gt; something I think is worth reiterating: assuming Bitcoin adoption&#xA;&gt; &gt; continues to grow at similar or accelerating rates, then eventually the&#xA;&gt; &gt; mempool is going to be filled with thousands of txs at all times whether&#xA;&gt; &gt; block limits are 1MB or 16MB&#xA;&gt;&#xA;&gt; This is hopefully true. :)&#xA;&gt;&#xA;&gt; There is an unbounded amount of demand for block space, and as such it&#xA;&gt; doesn’t benefit anyone if the amount of free transactions get out of hand.&#xA;&gt; Because freeloaders would definitely be able to completely suffocate&#xA;&gt; Bitcoin.&#xA;&gt;&#xA;&gt; In the mail posted by OP he makes clear that this is a proposal for a hard&#xA;&gt; fork to change the block size *limit*. The actual block size would not be&#xA;&gt; changed at the same time, it will continue being set based on market values&#xA;&gt; or whatever we decide between now and then.&#xA;&gt;&#xA;&gt; The block size itself should be set based on the amount of fees being paid&#xA;&gt; to miners to make a block.&#xA;&gt;&#xA;&gt; What we want is a true fee-market where the miner can decide to make a&#xA;&gt; block&#xA;&gt; smaller to get people to pay more fees, because if we were to go to 16MB&#xA;&gt; blocks in one go, the cost of the miner would go up, but his reward based&#xA;&gt; on&#xA;&gt; fees will go down!&#xA;&gt; A block so big that 100% of the transactions will always be mined in the&#xA;&gt; next block will just cause a large section of people to no longer feel the&#xA;&gt; need to pay fees.&#xA;&gt;&#xA;&gt; As such I don’t fear the situation where the block size limit goes up a lot&#xA;&gt; in one go, because it is not in anyone’s interest to make the actual block&#xA;&gt; size follow.&#xA;&gt; --&#xA;&gt; Tom Zander&#xA;&gt; Blog: https://zander.github.io&#xA;&gt; Vlog: https://vimeo.com/channels/tomscryptochannel&#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/20170330/dd71b786/attachment-0001.html&gt;</html></oembed>