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 9AE4FDAF for ; Wed, 2 Mar 2016 15:54:16 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-vk0-f45.google.com (mail-vk0-f45.google.com [209.85.213.45]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 35765193 for ; Wed, 2 Mar 2016 15:54:16 +0000 (UTC) Received: by mail-vk0-f45.google.com with SMTP id k196so206872299vka.0 for ; Wed, 02 Mar 2016 07:54:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:cc; bh=P+BztshTPSDStDlDck6cQgM7ygqCQ7ZqfC/9iisQmLs=; b=aIBrdqrs2P5eaeyTlSfJDT+duKaiA7c2huy2NrnmxFy+kiNKMM4vUGm8JHwynzPEra Cp+fhvUcb+YwIueVNNLwunQQ2+Xhe0ObzmzshKuEobb4X33yaiZdG+jhcYt7yGwvBrNA N2ROZcj7LRCwXCfx7YPU/LSVTBXAPKl+1sFROrYig8kqOpXORtEHE7nSlOra2SnPvKRo qUmNktMnLdk1YtYsVbebQ8PUdXhZLI8o7lisy9guc9AHt4tZfKkR9ZSjDgV10v0kz9lc dXynMoUvn9dCXkkK6ZpV7+hQjmFryTO1wh3vO/0qNMa8m5tShNcE4qJBooSpMNZJRNnK YeYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:cc; bh=P+BztshTPSDStDlDck6cQgM7ygqCQ7ZqfC/9iisQmLs=; b=i9vDZoZ/XmbARTEYe/ZaFwxlsay//+v0L+aZ05DG2aHiIJ7PJRIqv0gZ1Q1l3AAAde ixQ1rYDU9/DK5UL0dLfLYjgVrhAx0awTH7XuzTbjrbWk6uyXQuWudipC+nSS+bEHnE6c dSo4tl6PnfdkoWdm0+EVnYaAZ7azR7neKW9VhxmgJUKeU0fdmsNuAXgY95H8WxEitkCX NBE5T/rrkkFo3aqpg2gua46MFPEHARp2AFZVbSEiFb+2wd2ssCQ+F9g6anvRqyL4fLzZ VzPA+Ok9UkG9V/s6IGo0q5H2KrW82XxCVPawKANIoLdV1R40TtPb4vEX1So2KZbmDgLr Rtaw== X-Gm-Message-State: AD7BkJJ6Rxnq6PArCJLlb31kdCL4Rjk39qkSZuHT1RQMNvdOFJ+HXItp0san4gyeKqqJv7Tfsxaq+bGwNvpjXg== MIME-Version: 1.0 X-Received: by 10.31.10.199 with SMTP id 190mr21342243vkk.51.1456934055435; Wed, 02 Mar 2016 07:54:15 -0800 (PST) Received: by 10.159.37.137 with HTTP; Wed, 2 Mar 2016 07:54:15 -0800 (PST) In-Reply-To: References: <201603021456.15820.luke@dashjr.org> <201603021514.36769.luke@dashjr.org> Date: Wed, 2 Mar 2016 15:54:15 +0000 Message-ID: From: Tier Nolan Cc: Bitcoin Dev Content-Type: multipart/alternative; boundary=001a11440176d5e4cb052d12e46e X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,HTML_MESSAGE,MISSING_HEADERS, RCVD_IN_DNSWL_LOW autolearn=no version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Wed, 02 Mar 2016 15:59:39 +0000 Subject: Re: [bitcoin-dev] Hardfork to fix difficulty drop algorithm X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Mar 2016 15:54:16 -0000 --001a11440176d5e4cb052d12e46e Content-Type: text/plain; charset=UTF-8 If a hard-fork is being considered, the easiest is to just step the difficulty down by a factor of 2 when the adjustment happens. This means that miners still get paid the same minting fee per hash as before. There isn't that much risk. If the hashing power stays constant, then there will be 5 minute blocks for a while until everything readjusts. Nearly the same can be accomplished by a soft fork. Proposal: If 900 of the last 1000 blocks are block version X or above, then the smooth change rule applies. The adjustment is as follows big_number get_new_target(int height, big_number old_target) { if (height < 405000) return old_target; else if (height < 420000) return (old_target * 15000) / (height - 390000); else return old_target; } What this does is ramp up the difficulty slowly from 405,000 to 420,000. It ends up with a target that is 50% of the value stored in target bits. These blocks are valid since they have twice as much POW as normally required. For block 420000, the difficulty drops by 2 and the reward drops by 2 at the same time. This means that miners still get paid the same BTC per hash. It would mean 5 minute blocks until the next adjustment though. If 90% of the network are mining the artificially hard blocks, then a 10% fork still loses. The 90% has an effective hash rate of 45% vs the 10%. It is unlikely that miners would accept the fork, since they lose minting fees. It effectively brings the subsidy reduction forward in time. --001a11440176d5e4cb052d12e46e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
If a hard-fork is being= considered, the easiest is to just step the difficulty down by a factor of= 2 when the adjustment happens.

This means that miners st= ill get paid the same minting fee per hash as before.=C2=A0 There isn't= that much risk.=C2=A0 If the hashing power stays constant, then there will= be 5 minute blocks for a while until everything readjusts.
<= br>
Nearly the same can be accomplished by a soft fork= .

Proposal:

If 900 of the last 1= 000 blocks are block version X or above, then the smooth change rule applie= s.

The adjustment is as follows

big_number get_ne= w_target(int height, big_number old_target) {
=C2=A0=C2=A0=C2=A0 i= f (height < 405000)
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 = return old_target;
=C2=A0=C2=A0=C2=A0 else if (height < 420000)=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return (old_target * 1= 5000) / (height - 390000);
=C2=A0=C2=A0=C2=A0 else
= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return old_target;
}

<= /div>
What this does is ramp up the difficulty slowly from 405,000 to 4= 20,000.=C2=A0 It ends up with a target that is 50% of the value stored in t= arget bits.=C2=A0 These blocks are valid since they have twice as much POW = as normally required.

For block 420000, the difficulty drops by 2 and the reward drops by 2 at=20 the same time.=C2=A0 This means that miners still get paid the same BTC per= =20 hash.=C2=A0 It would mean 5 minute blocks until the next adjustment though.=

If 90% of the network are mining the artificially hard blocks, then a=C2=A0 10% fork still loses.=C2=A0 The 90% has an effective hash rate of 45% vs th= e 10%.

It is unlikely that miners would accept the fork, = since they lose minting fees.=C2=A0 It effectively brings the subsidy reduc= tion forward in time.
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