From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 6A180727 for ; Sat, 8 Apr 2017 14:35:33 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-wm0-f54.google.com (mail-wm0-f54.google.com [74.125.82.54]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 9E21C186 for ; Sat, 8 Apr 2017 14:35:32 +0000 (UTC) Received: by mail-wm0-f54.google.com with SMTP id w64so10487136wma.0 for ; Sat, 08 Apr 2017 07:35:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=FENJcUIycttol+kxsDGswT8t1OKyHW0OSQ5/ovWv8/Y=; b=m8X71JhSiNsqqnDXZP6QtZdyodID2pSxGqHhBCVYeuwwqt1HwfnsaeyoQbNljcxE9I 6wbg8NjlMDZEF/slxo527Bx5IbAJZI64OmbPGDv5eI8X1QWak/CmUXm5wqDOtHhQT9q6 LD1gb+xYmwWT5ytxiUUYn8HcAResP3Wi52xJSMhKElF6Rb9oCO6sfGf4LgU3q8GEMbf0 Ai7Gngh+PoS5G7Xzy+ptkrzqlp7XY1j495J9un5pqrh1wUJabMTVPG49e0vQLD9T9iPB hYSZJFK+ACbWACynzOZz3yGah0wBeSv4ppkLELuOhtxWuvqXjoG8slo2R2eqvTp28n7A kV7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=FENJcUIycttol+kxsDGswT8t1OKyHW0OSQ5/ovWv8/Y=; b=UdBTANMSr2GNs2gw+soJJGnsGX7OEzJp0r9e4ZzqaxCxAVUBy946VPKv8kSEglh6PN DVuULcaq2PwYUfIL6ONAdLlydOtQjim5GV1oWk0AgBE0mBoy8D6hlT01B4vJdgOQPOtI uz3fZu301trR4mfkZVxoUuP4DPWs842WVhM8Xz0cvXFheaoLaNcV4BkBl0QXek9U358J mn0PcnXPIIKm+dNEXKkYrAV2YdBWWsdXYEUEqXprB+i/mJA/y8nlVKlRCquiyB8xmm7T tRkjfa78zYiLuYzWZl3FVA/rYNFqkPlz5xbYKVaKUD0CWj/N1RC1UURZRR8BY6MSjxOu zxuw== X-Gm-Message-State: AN3rC/6wsfNsem63LZPee0QXD3csKwiiNdtmCw11OFECqpKfEY38MrzAm7MkfDbPmTal7+X67CjBM3OFVPZSsQ== X-Received: by 10.28.60.6 with SMTP id j6mr3352966wma.19.1491662131304; Sat, 08 Apr 2017 07:35:31 -0700 (PDT) MIME-Version: 1.0 Received: by 10.223.169.246 with HTTP; Sat, 8 Apr 2017 07:35:30 -0700 (PDT) In-Reply-To: References: From: Jimmy Song Date: Sat, 8 Apr 2017 09:35:30 -0500 Message-ID: To: Pavel Moravec Content-Type: multipart/alternative; boundary=001a1148e60a7622b0054ca8a77f X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, HTML_MESSAGE, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Sat, 08 Apr 2017 14:38:55 +0000 Cc: Bitcoin Protocol Discussion Subject: Re: [bitcoin-dev] A Small Modification to Segwit X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 08 Apr 2017 14:35:33 -0000 --001a1148e60a7622b0054ca8a77f Content-Type: text/plain; charset=UTF-8 Pavel, Until all miners update (firmware or hardware), the change encourages > large difference in mining efficiency. And IMO it gives another > advantage to large mining operations in general. > Certainly, there would have to be changes for stratum, pool software, etc. But the monetary incentives align to all the changes needed. Remember, overt ASICBoost can get something like a 12.5% efficiency boost from toggling a single bit in the version (equivalent to 2 colliding work items), 18.5% from 2 bits (equivalent to 4 colliding work items), 23.4% from 4 bits (see https://arxiv.org/ftp/arxiv/papers/1604/1604.00575.pdf). In lieu of an explicit allowance of overt ASICBoost, the monetary incentives lead to odd BIP9 signaling, especially if 4 or more proposals signal at once. There really isn't a practical way to block overt ASICBoost without forcing the version bits to be some value. In other words, the question isn't about allowing/disallowing ASICBoost at this point. The question is whether we want ASICBoost open or hidden. > You make a strong assumption that the new optimization is not > compatible with overt ASICBoost. If it is compatible, ASICBoost > doesn't help you with "defending against" the new optimization at all. > And it can be the case that the new optimization is based on ASICBoost > so you can make the situation "worse" by allowing it. > This would only be the case if overt ASICBoost were not possible at all. It is currently possible to use overt ASICBoost, so optimizations based on overt ASICBoost would also be possible unless something were done to actively block it. > Certainly, if only one company made use of the extra nonce space, they > would have an advantage. > > Can you explain why the reality should be significantly different? In > sufficiently near future. Market incentives, I would imagine. How quickly that would be is not something I'm qualified to answer. > We don't have to deal with any such theoretical situation now. You > proposal goes in opposite direction, by adding support for patented > algorithm. I don't know myself what the possible legal implications > are (maybe only for a subset of miners) so I consider it as an > unnecessary risk. At least before some conclusive legal analysis says > differently. > I'm not adding support as much as explicitly allowing what's implicitly allowed. Whatever risks you imagine for this proposal exist on the network currently, with unmodified BIP-141 and with modified BIP-141. The difference in adding the modification is that overt ASICBoost is explicitly allowed in the modified BIP-141 as to not hide it. Jimmy --001a1148e60a7622b0054ca8a77f Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Pavel,

Until all miners update (firmware or hardware), the change encourages
large difference in mining efficiency. And IMO it gives another
advantage to large mining operations in general.
=

Certainly, there would have to be c= hanges for stratum, pool software, etc. But the monetary incentives align t= o all the changes needed.=C2=A0

Remember, overt AS= ICBoost can get something like a 12.5% efficiency boost from toggling a sin= gle bit in the version (equivalent to 2 colliding work items), 18.5% from 2= bits (equivalent to 4 colliding work items), 23.4% from 4 bits (see https://arxiv.= org/ftp/arxiv/papers/1604/1604.00575.pdf). In lieu of an explicit allow= ance of overt ASICBoost, the monetary incentives lead to odd BIP9 signaling= , especially if 4 or more proposals signal at once. There really isn't = a practical way to block overt ASICBoost without forcing the version bits t= o be some value.

In other words, the question isn&= #39;t about allowing/disallowing ASICBoost at this point. The question is w= hether we want ASICBoost open or hidden.
=C2=A0
You make a strong assumption that= the new optimization is not
compatible with overt ASICBoost. If it is compatible, ASICBoost
doesn't help you with "defending against" the new optimizatio= n at all.
And it can be the case that the new optimization is based on ASICBoost
so you can make the situation "worse" by allowing it.

This would only be the case if overt ASICBoost wer= e not possible at all. It is currently possible to use overt ASICBoost, so = optimizations based on overt ASICBoost would also be possible unless someth= ing were done to actively block it.

> Certainly, if only one company made use of the extra nonce space, they= would have an advantage.

Can you explain why the reality should be significantly different? I= n
sufficiently near future.

Market incentives= , I would imagine. How quickly that would be is not something I'm quali= fied to answer.
=C2=A0
We don't have to deal with any such theoretical situat= ion now. You
proposal goes in opposite direction, by adding support for patented
algorithm. I don't know myself what the possible legal implications
are (maybe only for a subset of miners) so I consider it as an
unnecessary risk. At least before some conclusive legal analysis says
differently.

I'm not adding = support as much as explicitly allowing what's implicitly allowed. Whate= ver risks you imagine for this proposal exist on the network currently, wit= h unmodified BIP-141 and with modified BIP-141. The difference in adding th= e modification is that overt ASICBoost is explicitly allowed in the modifie= d BIP-141 as to not hide it.

Jimmy --001a1148e60a7622b0054ca8a77f--