Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 40BE51DDA for ; Tue, 29 Sep 2015 14:04:46 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-ob0-f177.google.com (mail-ob0-f177.google.com [209.85.214.177]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id E64FC220 for ; Tue, 29 Sep 2015 14:04:39 +0000 (UTC) Received: by obbda8 with SMTP id da8so6094827obb.1 for ; Tue, 29 Sep 2015 07:04:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:cc:content-type; bh=AtTeoB8SVg04XvipogU8B0WS8xcYYV0GBjhaLPmMwh8=; b=ze42yGEdhSF+KuyZptG+a+eAZJBlPiex8OMEK6l1OjGB1jjAUQIEoZK0sLFCdCZG5q xqHjfzr77vIa4s5YfT0lPuc7sY+HhWr8Z00krstQgueqSX4nxC5qDXQiZcQmfGcKn/fA KZmd9u07j3xzpsb3+34eHIuVDk/8dyyJb81XK9j+uVT1euB4e3/X5+Q/7mrXS31Biud5 q0DQ5ChxNqEHZYpiPbLs0fIBfza54Kq5BqHfTMub8U0kO826psyyJAkCX7J0Z0iVa+E3 lKoO0waY5W1I1KX9PtahycNhGE/71T0z/Mj6rMbNiPJVcJxG5AXwC86dfovZ6U8Oa+A5 f96A== MIME-Version: 1.0 X-Received: by 10.182.142.129 with SMTP id rw1mr14377228obb.28.1443535479158; Tue, 29 Sep 2015 07:04:39 -0700 (PDT) Received: by 10.60.58.134 with HTTP; Tue, 29 Sep 2015 07:04:39 -0700 (PDT) Date: Tue, 29 Sep 2015 10:04:39 -0400 Message-ID: From: Gavin Andresen To: "Jonathan Toomim (Toomim Bros)" Content-Type: multipart/alternative; boundary=001a11c1ccfa74bff90520e34b81 X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_05,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Bitcoin Dev Subject: [bitcoin-dev] Is it possible for there to be two chains after a hard fork? 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: Tue, 29 Sep 2015 14:04:46 -0000 --001a11c1ccfa74bff90520e34b81 Content-Type: text/plain; charset=UTF-8 I keep seeing statements like this: On Tue, Sep 29, 2015 at 9:30 AM, Jonathan Toomim (Toomim Bros) via bitcoin-dev wrote: > As a further benefit to hard forks, anybody who is ideologically opposed > to the change can continue to use the old version successfully, as long as > there are enough miners to keep the fork alive. ... but I can't see how that would work. Lets say there is a hard fork, and 5% of miners stubbornly refuse to go along with the 95% majority (for this thought experiment, it doesn't matter if the old rules or new rules 'win'). Lets further imagine that some exchange decides to support that 5% and lets people trade coins from that fork (one of the small altcoin exchanges would definitely do this if they think they can make a profit). Now, lets say I've got a lot of pre-fork bitcoin; they're valid on both sides of the fork. I support the 95% chain (because I'm not insane), but I'm happy to take people's money if they're stupid enough to give it to me. So, I do the following: 1) Create a send-to-self transaction on the 95% fork that is ONLY valid on the 95% fork (maybe I CoinJoin with a post-fork coinbase transaction, or just move my coins into then out of an exchange's very active hot wallet so I get coins with a long transaction history on the 95% side of the fork). 2) Transfer those same coins to the 5% exchange and sell them for whatever price I can get (I don't care how low, it is free money to me-- I will still own the coins on the 95% fork). I have to do step (1) to prevent the exchange from taking the transfer-to-exchange transaction and replaying it on the 95% chain. I don't see any way of preventing EVERYBODY who has coins on the 95% side of the fork from doing that. The result would be a huge free-fall in price as I, and everybody else, rushes to get some free money from anybody willing to pay us to remain idealogically pure. Does anybody think something else would happen, and do you think that ANYBODY would stick to the 5% fork in the face of enormously long transaction confirmation times (~3 hours), a huge transaction backlog as lots of the 95%'ers try to sell their coins before the price drops, and a massive price drop for coins on the 5% fork. -- -- Gavin Andresen --001a11c1ccfa74bff90520e34b81 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I ke= ep seeing statements like this:

<= div class=3D"gmail_quote">On Tue, Sep 29, 2015 at 9:30 AM, Jonathan Toomim = (Toomim Bros) via bitcoin-dev <bitcoin-dev@lists.linux= foundation.org> wrote:
As a= further benefit to hard forks, anybody who is ideologically opposed to the= change can continue to use the old version successfully, as long as there = are enough miners to keep the fork alive.

... but I c= an't see how that would work.

Lets say there is a hard fork, and 5% of miners= stubbornly refuse to go along with the 95% majority (for this thought expe= riment, it doesn't matter if the old rules or new rules 'win').=

Lets = further imagine that some exchange decides to support that 5% and lets peop= le trade coins from that fork (one of the small altcoin exchanges would def= initely do this if they think they can make a profit).

Now, lets say I've got= a lot of pre-fork bitcoin; they're valid on both sides of the fork. I = support the 95% chain (because I'm not insane), but I'm happy to ta= ke people's money if they're stupid enough to give it to me.
<= div class=3D"gmail_extra">
So, I do the= following:

1) Create a send-to-self transaction on the 95% fork that is ONLY val= id on the 95% fork (maybe I CoinJoin with a post-fork coinbase transaction,= or just move my coins into then out of an exchange's very active hot w= allet so I get coins with a long transaction history on the 95% side of the= fork).

2) Transfer =C2=A0those same coins to the 5% exchange and sell them for w= hatever price I can get (I don't care how low, it is free money to me--= I will still own the coins on the 95% fork).

I have to do step (1) to prevent th= e exchange from taking the transfer-to-exchange transaction and replaying i= t on the 95% chain.

I don't see any way of preventing EVERYBODY = who has coins on the 95% side of the fork from doing that. The result would= be a huge free-fall in price as I, and everybody else, rushes to get some = free money from anybody willing to pay us to remain idealogically pure.

Does anyb= ody think something else would happen, and do you think that ANYBODY would = stick to the 5% fork in the face of enormously long transaction confirmatio= n times (~3 hours), a huge transaction backlog as lots of the 95%'ers t= ry to sell their coins before the price drops, and a massive price drop for= coins on the 5% fork.

--
--
Gavin Andresen

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