<oembed><type>rich</type><version>1.0</version><author_name>npub1ddqaln8xsfmy6sxqplt9sz5ev99kh052sveqsh02q7hmc3a6n68shpgp9a</author_name><author_url>https://nostr.ae/npub1ddqaln8xsfmy6sxqplt9sz5ev99kh052sveqsh02q7hmc3a6n68shpgp9a</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2017-04-08&#xA;📝 Original message:Yes, you only need a few bits in the version number, probably less than 8.&#xA;&#xA;If you encourage the overt method of using AsicBoost I would argue that you&#xA;no longer need to dis-encourage the couvert method anymore as in Greg&#39;s&#xA;proposal. Nobody would use the couvert method anyway because the overt&#xA;method is so much simpler. So maybe the proposals can be completely&#xA;disentangled?&#xA;&#xA;&#xA;On Fri, Apr 7, 2017 at 5:05 PM, Jimmy Song via bitcoin-dev &lt;&#xA;bitcoin-dev at lists.linuxfoundation.org&gt; wrote:&#xA;&#xA;&gt; I&#39;ve gotten feedback from Adam Back that you actually don&#39;t need all 32&#xA;&gt; bits in the header for overt ASICBoost, so I&#39;m modifying my proposal. Of&#xA;&gt; the 32-bit version field, bits 16 to 23 are reserved for miners, the&#xA;&gt; witness commitment stays as defined in BIP-141 except that it&#39;s now&#xA;&gt; required. BIP9 then is modified so that bits 16 to 23 are now no longer&#xA;&gt; usable.&#xA;&gt;&#xA;&gt; On Fri, Apr 7, 2017 at 3:06 PM, Jimmy Song &lt;jaejoon at gmail.com&gt; wrote:&#xA;&gt;&#xA;&gt;&gt; Hey everyone, This is an idea that I had about Segwit and Gregory&#39;s&#xA;&gt;&gt; proposal from yesterday that I wanted to run by everyone on this list. I&#39;m&#xA;&gt;&gt; not at all sure what this would mean for non-upgraded nodes on the network&#xA;&gt;&gt; and would like feedback on that. This is not a formal BIP as it&#39;s a&#xA;&gt;&gt; modification to a previously submitted one, but I&#39;m happy to formalize it&#xA;&gt;&gt; if it would help.&#xA;&gt;&gt; ----------------------------------------&#xA;&gt;&gt; MotivationOne of the interesting aspects of Gregory Maxwell’s proposal&#xA;&gt;&gt; is that it only precludes the covert version of ASICBoost. He&#xA;&gt;&gt; specifically left the overt version alone.&#xA;&gt;&gt;&#xA;&gt;&gt; Overt ASICBoost requires grinding on the version bits of the Block&#xA;&gt;&gt; header instead of the Merkle Root. This is likely more efficient than the&#xA;&gt;&gt; Merkle Root grinding (aka covert ASICBoost) and requires way less&#xA;&gt;&gt; resources (much less RAM, SHA256 calculations, no tx shuffling, etc).&#xA;&gt;&gt;&#xA;&gt;&gt; If we combine Gregory Maxwell’s proposal with BIP-141 (Segwit) and add a&#xA;&gt;&gt; slight modification, this should, in theory, make ASICBoost a lot more&#xA;&gt;&gt; useful to miners and appeal to their financial interests.&#xA;&gt;&gt; The Modification&#xA;&gt;&gt;&#xA;&gt;&gt; Currently, the version bits (currently 4 bytes, or 32 bits) in the header&#xA;&gt;&gt; are used for BIP9 signaling. We change the version bits to a nonce-space so&#xA;&gt;&gt; the miners can use it for overt ASICBoost. The 32-bits are now moved&#xA;&gt;&gt; over to the Coinbase transaction as part of the witness commitment. The&#xA;&gt;&gt; witness commitment goes from 38 bytes to 42 bytes, with the last 4 bytes&#xA;&gt;&gt; being used as the version bits in the block header previously. The witness&#xA;&gt;&gt; commitment becomes required as per Gregory Maxwell’s proposal.&#xA;&gt;&gt; Reasoning&#xA;&gt;&gt;&#xA;&gt;&gt; First, this brings ASICBoost out into the open. Covert ASICBoost becomes&#xA;&gt;&gt; much more costly and overt ASICBoost is now encouraged.&#xA;&gt;&gt;&#xA;&gt;&gt; Second, we can make this change relatively quickly. Most of the Segwit&#xA;&gt;&gt; testing stays valid and this change can be deployed relatively quickly.&#xA;&gt;&gt;&#xA;&gt;&gt; Note on SPV clients&#xA;&gt;&gt;&#xA;&gt;&gt; Currently Segwit stores the witness commitment in the Coinbase tx, so&#xA;&gt;&gt; lightweight clients will need to get the Coinbase tx + Merkle proof to&#xA;&gt;&gt; validate segwit transactions anyway. Putting block version information in&#xA;&gt;&gt; the Coinbase tx will not impose an extra burden on upgraded light clients.&#xA;&gt;&gt;&#xA;&gt;&#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/20170408/47873dc2/attachment-0001.html&gt;</html></oembed>