<oembed><type>rich</type><version>1.0</version><author_name>npub1g6vxlp4e0nyhs2dqxxcryztyf5f5hyuaq93nw4r87zcnv0sdsa0qqsl5wd</author_name><author_url>https://nostr.ae/npub1g6vxlp4e0nyhs2dqxxcryztyf5f5hyuaq93nw4r87zcnv0sdsa0qqsl5wd</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2016-05-10&#xA;📝 Original message:The various chunks in the double SHA256 are&#xA;&#xA;Chunk 1: 64 bytes&#xA;version&#xA;previous_block_digest&#xA;merkle_root[31:4]&#xA;&#xA;Chunk 2: 64 bytes&#xA;merkle_root[3:0]&#xA;nonce&#xA;timestamp&#xA;target&#xA;&#xA;Chunk 3: 64 bytes&#xA;digest from first sha pass&#xA;&#xA;Their improvement requires that all data in Chunk 2 is identical except for&#xA;the nonce.  With 4 bytes, the birthday paradox means collisions can be&#xA;found reasonable easily.&#xA;&#xA;If hard forks are allowed, then moving more of the merkle root into the 2nd&#xA;chunk would make things harder.  The timestamp and target could be moved&#xA;into chunk 1.  This increases the merkle root to 12 bytes in the 2nd&#xA;chunk.  Finding collisions would be made much more difficult.&#xA;&#xA;If ASIC limitations mean that the nonce must stay where it is, this would&#xA;mean that the merkle root would be split into two pieces.&#xA;&#xA;On Tue, May 10, 2016 at 7:57 PM, Peter Todd via bitcoin-dev &lt;&#xA;bitcoin-dev at lists.linuxfoundation.org&gt; wrote:&#xA;&#xA;&gt; As part of the hard-fork proposed in the HK agreement(1) we&#39;d like to make&#xA;&gt; the&#xA;&gt; patented AsicBoost optimisation useless, and hopefully make further similar&#xA;&gt; optimizations useless as well.&#xA;&gt;&#xA;&gt; What&#39;s the best way to do this? Ideally this would be SPV compatible, but&#xA;&gt; if it&#xA;&gt; requires changes from SPV clients that&#39;s ok too. Also the fix this should&#xA;&gt; be&#xA;&gt; compatible with existing mining hardware.&#xA;&gt;&#xA;&gt;&#xA;&gt; 1)&#xA;&gt; https://medium.com/@bitcoinroundtable/bitcoin-roundtable-consensus-266d475a61ff&#xA;&gt;&#xA;&gt; 2)&#xA;&gt; http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2016-April/012596.html&#xA;&gt;&#xA;&gt; --&#xA;&gt; https://petertodd.org &#39;peter&#39;[:-1]@petertodd.org&#xA;&gt;&#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;&gt;&#xA;-------------- next part --------------&#xA;An HTML attachment was scrubbed...&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20160510/cb6a2690/attachment.html&gt;</html></oembed>