Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 6C71410F8 for ; Tue, 8 Sep 2015 14:02:55 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-ig0-f178.google.com (mail-ig0-f178.google.com [209.85.213.178]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id A8CDD160 for ; Tue, 8 Sep 2015 14:02:54 +0000 (UTC) Received: by igbni9 with SMTP id ni9so77660080igb.0 for ; Tue, 08 Sep 2015 07:02:54 -0700 (PDT) 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:to :cc:content-type; bh=IBVQSEMjIdKkn6ARv6yN1T/40K2Roco0Fflc8TVoGWU=; b=yfUAiVaT5OzPWf48103DDHnjhFUr2QXMg4K8xP9d0vvUjATRS1QgamspMoSlkvR90m ZJoSzQLSmskJJROg9FHeFxRhwtzm3lHi2wmcoo6IFP19gAAuTVuRd+nfmuCWDUOrl1wv 9y3tn1k/BMDhwnD17bDskSkf8XRtOuivGutIduVmdhy2UzGlpDbaR1csQUERPe3Z//kq x/j9Aj1oanF9zpjSr++R2toAL4vQqNTRKIcKdnTNaOb7RYkvL36UF4LLiLXaS13yxoJ9 GRmDKqyh9jdeeH1/gglMvKFYsNUvO2Pl3wsti48Bff0nrqxfW6Vn71L242eyj4cOoAKu 9pag== MIME-Version: 1.0 X-Received: by 10.50.90.180 with SMTP id bx20mr43087264igb.53.1441720971312; Tue, 08 Sep 2015 07:02:51 -0700 (PDT) Received: by 10.107.178.12 with HTTP; Tue, 8 Sep 2015 07:02:51 -0700 (PDT) In-Reply-To: References: Date: Wed, 9 Sep 2015 00:02:51 +1000 Message-ID: From: Washington Sanchez To: Adam Back Content-Type: multipart/alternative; boundary=047d7bea3d285c4488051f3cd2ba X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,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: Re: [bitcoin-dev] Dynamic limit to the block size - BIP draft discussion 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, 08 Sep 2015 14:02:55 -0000 --047d7bea3d285c4488051f3cd2ba Content-Type: text/plain; charset=UTF-8 > > The maximum block-size is one that can be filled at zero-cost by > miners, and so allows some kinds of amplification of selfish-mining > related attacks A selfish mining attack would have to be performed for at least 2000 blocks over a period of 4 weeks in order to achieve a meager 10% increase in the block size. If there goal is to simply drive up fees to gain acceptance into the block, we're in exactly the same position we are in today (as in nothing stops a miner from doing this). If the goal is to increase the block size to push out smaller miners, they'll have to perform this attack over the course of years and destroy any economic incentives they have for mining in the first place. why give this power up to a subsection of the ecosystem in order to make > it easier to change or game Well this same could be said for developers trying to predict what the appropriate block size should be over the next 20 years... it's a hallmark to a group of bankers trying to predict the appropriate interest rate for the entire economy. Just as it is impossible to predict the appropriate hash rate to secure the network, so it goes for the block size. Both need to adjust dynamically to the scale/adoption of the network. On Tue, Sep 8, 2015 at 11:13 PM, Adam Back wrote: > The maximum block-size is one that can be filled at zero-cost by > miners, and so allows some kinds of amplification of selfish-mining > related attacks. > > Adam > > > On 8 September 2015 at 13:28, Ivan Brightly via bitcoin-dev > wrote: > > This is true, but miners already control block size through soft caps. > > Miners are fully capable of producing smaller blocks regardless of the > max > > block limit, with or without collusion. Arguably, there is no need to > ever > > reduce the max block size unless technology advances for some reason > reverse > > course - aka, WW3 takes a toll on the internet and the average bandwidth > > available halves. The likelihood of significant technology contraction in > > the near future seems rather unlikely and is more broadly problematic for > > society than bitcoin specifically. > > > > The only reason for reducing the max block limit other than technology > > availability is if you think that this is what will produce the fee > market, > > which is back to an economic discussion - not a technology scaling > > discussion. > > > > On Tue, Sep 8, 2015 at 4:49 AM, Btc Drak via bitcoin-dev > > wrote: > >> > >> > but allow meaningful relief to transaction volume pressure in response > >> > to true market demand > >> > >> If blocksize can only increase then it's like a market that only goes > >> up which is unrealistic. Transaction will volume ebb and flow > >> significantly. Some people have been looking at transaction volume > >> charts over time and all they can see is an exponential curve which > >> they think will go on forever, yet nothing goes up forever and it will > >> go through significant trend cycles (like everything does). If you > >> dont want to hurt the fee market, the blocksize has to be elastic and > >> allow contraction as well as expansion. > > > > > > _______________________________________________ > > bitcoin-dev mailing list > > bitcoin-dev@lists.linuxfoundation.org > > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > > > -- ------------------------------------------- *Dr Washington Y. Sanchez * Co-founder, OB1 Core developer of OpenBazaar @drwasho --047d7bea3d285c4488051f3cd2ba Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
The maxi= mum block-size is one that can be filled at zero-cost by
miners, and so allows s= ome kinds of amplification of selfish-mining
related attacks
=

A selfish mining attack would have to be performed for = at least 2000 blocks over a period of 4 weeks in order to achieve a meager = 10% increase in the block size.=C2=A0

If there goa= l is to simply drive up fees to gain acceptance into the block, we're i= n exactly the same position we are in today (as in nothing stops a miner fr= om doing this).=C2=A0
If the goal is to increase the block size t= o push out smaller miners, they'll have to perform this attack over the= course of years and destroy any economic incentives they have for mining i= n the first place.

=C2=A0why give this power up to a subsection of the ecosystem= in order to make it easier to change or game

<= /div>
Well this same could be said for developers trying to predict wha= t the appropriate block size should be over the next 20 years... it's a= hallmark to a group of bankers trying to predict the appropriate interest = rate for the entire economy. Just as it is impossible to predict the approp= riate hash rate to secure the network, so it goes for the block size. Both = need to adjust dynamically to the scale/adoption of the network.

On Tue, Sep 8, 2= 015 at 11:13 PM, Adam Back <adam@cypherspace.org> wrote:<= br>
The maximum block-size is one that can be= filled at zero-cost by
miners, and so allows some kinds of amplification of selfish-mining
related attacks.

Adam


On 8 September 2015 at 13:28, Ivan Brightly via bitcoin-dev
<bitcoin-dev@lists.linuxfoundation.org> wro= te:
> This is true, but miners already control block size through soft caps.=
> Miners are fully capable of producing smaller blocks regardless of the= max
> block limit, with or without collusion. Arguably, there is no need to = ever
> reduce the max block size unless technology advances for some reason r= everse
> course - aka, WW3 takes a toll on the internet and the average bandwid= th
> available halves. The likelihood of significant technology contraction= in
> the near future seems rather unlikely and is more broadly problematic = for
> society than bitcoin specifically.
>
> The only reason for reducing the max block limit other than technology=
> availability is if you think that this is what will produce the fee ma= rket,
> which is back to an economic discussion - not a technology scaling
> discussion.
>
> On Tue, Sep 8, 2015 at 4:49 AM, Btc Drak via bitcoin-dev
> <bitcoin-d= ev@lists.linuxfoundation.org> wrote:
>>
>> > but allow meaningful relief to transaction volume pressure in= response
>> > to true market demand
>>
>> If blocksize can only increase then it's like a market that on= ly goes
>> up which is unrealistic. Transaction will volume ebb and flow
>> significantly. Some people have been looking at transaction volume=
>> charts over time and all they can see is an exponential curve whic= h
>> they think will go on forever, yet nothing goes up forever and it = will
>> go through significant trend cycles (like everything does). If you=
>> dont want to hurt the fee market, the blocksize has to be elastic = and
>> allow contraction as well as expansion.
>
>
> __________________= _____________________________
> bitcoin-dev mailing list
> bitcoin-dev@l= ists.linuxfoundation.org
> https://lists.linuxfoundation.org= /mailman/listinfo/bitcoin-dev
>



--
=
=
-------------------------------------------
Co-founder, OB1=
Core developer of OpenBazaar

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