Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 31484B2E for ; Tue, 29 Sep 2015 14:17:40 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from d.mail.sonic.net (d.mail.sonic.net [64.142.111.50]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 943EE2F for ; Tue, 29 Sep 2015 14:17:39 +0000 (UTC) Received: from [192.168.1.190] (63.135.62.197.nwinternet.com [63.135.62.197] (may be forged)) (authenticated bits=0) by d.mail.sonic.net (8.15.1/8.15.1) with ESMTPSA id t8TEHZLh028458 (version=TLSv1 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Tue, 29 Sep 2015 07:17:36 -0700 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Content-Type: multipart/signed; boundary="Apple-Mail=_74C663F9-EECE-4FD2-AACC-7FA080477E44"; protocol="application/pgp-signature"; micalg=pgp-sha512 X-Pgp-Agent: GPGMail 2.5.1 From: "Jonathan Toomim (Toomim Bros)" In-Reply-To: Date: Tue, 29 Sep 2015 07:17:35 -0700 Message-Id: <0DCA91F5-E6D3-49CB-B473-D1AE1D3D9885@toom.im> References: To: Gavin Andresen X-Mailer: Apple Mail (2.1878.6) X-Sonic-CAuth: UmFuZG9tSVb9ywHyRoqxA91w6T7Dxuctgv8hoGuYCR0roMFxfH24vKVIHh5LD7M0A3v1kSN/B9IBzEJgbBeEumgqaxXeyn7C X-Sonic-ID: C;jBvW1LRm5RGJGeK7sH9FTg== M;MpFL1bRm5RGJGeK7sH9FTg== X-Sonic-Spam-Details: 0.0/5.0 by cerberusd X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,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: Re: [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 14:17:40 -0000 --Apple-Mail=_74C663F9-EECE-4FD2-AACC-7FA080477E44 Content-Type: multipart/alternative; boundary="Apple-Mail=_16AD04F3-1D28-4CF5-850B-1C24951A3457" --Apple-Mail=_16AD04F3-1D28-4CF5-850B-1C24951A3457 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii At the 95% threshold, I don't think it would happen unless there was a = very strong motivating factor, like a small group believing that CLTV = was a conspiracy run by the NSA agent John Titor to contaminate our = precious bodily fluids with time-traveling traveler's cheques. At the 75% threshold, I think it could happen with mostly rational = users, but even then it's not very likely with most forks. With the = blocksize issue, there are some people who get very religious about = things like decentralization or fee markets and think that even 1 MB is = too large; I could see them making financial sacrifices in order to try = to make a small-block parallel fork a reality, one that is true to their = vision of what's needed to make Bitcoin true and pure, or whatever. On Sep 29, 2015, at 7:04 AM, Gavin Andresen = wrote: > I keep seeing statements like this: >=20 > 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. >=20 > ... but I can't see how that would work. >=20 > 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'). >=20 > 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). >=20 > 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. >=20 > So, I do the following: >=20 > 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). >=20 > 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). >=20 > I have to do step (1) to prevent the exchange from taking the = transfer-to-exchange transaction and replaying it on the 95% chain. >=20 > 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. >=20 > 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. >=20 > -- > -- > Gavin Andresen >=20 --Apple-Mail=_16AD04F3-1D28-4CF5-850B-1C24951A3457 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii At the = 95% threshold, I don't think it would happen unless there was a very = strong motivating factor, like a small group believing that CLTV was a = conspiracy run by the NSA agent John Titor to contaminate our precious = bodily fluids with time-traveling traveler's = cheques. 

At the 75% threshold, I think it could = happen with mostly rational users, but even then it's not very likely = with most forks. With the blocksize issue, there are some people who get = very religious about things like decentralization or fee markets and = think that even 1 MB is too large; I could see them making financial = sacrifices in order to try to make a small-block parallel fork a = reality, one that is true to their vision of what's needed to make = Bitcoin true and pure, or = whatever.




On Sep 29, 2015, at 7:04 AM, Gavin Andresen <gavinandresen@gmail.com> = wrote:

I keep seeing statements like this:

On Tue, Sep = 29, 2015 at 9:30 AM, Jonathan Toomim (Toomim Bros) via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.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 = 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


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