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From: Mark Friedenbach <mark@friedenbach.org>
Date: Fri, 7 Aug 2015 14:27:48 -0700
Message-ID: <CAOG=w-sCULNw=C75iot=6q4Yb16VvYh=F4DahS3ZEkEpGLvu3w@mail.gmail.com>
To: Sergio Demian Lerner <sergio.d.lerner@gmail.com>
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Cc: Bitcoin Dev <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] If you had a single chance to double the
 transactions/second Bitcoin allows...
Precedence: list

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Because halving the block interval comes with costs to SPV proofs (which
double the number of headers) and mining centralization (doubles the
selfish mining effect of latency) for the questionable benefit of a block
expectation time that is still measured in minutes, not seconds.

Doubling the block size is safer than halving the block interval, for the
same effect in aggregate transactions per second.

On Fri, Aug 7, 2015 at 2:18 PM, Sergio Demian Lerner via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

> What would you do?
>
> a. Double the block size
> b. Reduce the block rate to a half (average 5 minute blocks)
>
> Suppose this is a one time hard fork. There no drastic technical problems
> with any of them: "SPV" mining and the relay network has shown that block
> propagation is not an issue for such as small change. Mining centralization
> won't radically change for a 2x adjustment.
>
> So what would be best for Bitcoin?
>
> I suspect some (if not most of you) would choose b. Because reducing the
> block interval saves us real time. Waiting 30 minutes for a 3-block
> confirmation is... such a long time! Time that we value. Time that
> sometimes we waste waiting. Time that makes a difference for us. Doubling
> the block size does not change the user perception of Bitcoin in any way.
>
> Then why most discussions go around doubling the block size?
>
> Each change require less than 20 lines of code (*) in the reference code,
> and minimum change in other wallets.
>
> Currently there is no idle mining hardware for hire, so the security of
> six 10-minute block confirmation is equivalent to the security of six
> 5-minute block confirmations, as described in Satoshi's paper (if there
> were 51% spare mining hardware for hire, then obviously hiring that
> hardware for 30 minutes would cost less than hiring it for 1 hour).
>
> Why we discuss a 2x block size increase and not a 1/2 block interval
> reduction? Aren't we Bitcoin users after all?
>
> Best regards,
>  Sergio.
>
> (*) b requires increasing the transaction version number, to support the
> old nLockTime rate.
>
>
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
>

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<div dir=3D"ltr"><div>Because halving the block interval comes with costs t=
o SPV proofs (which double the number of headers) and mining centralization=
 (doubles the selfish mining effect of latency) for the questionable benefi=
t of a block expectation time that is still measured in minutes, not second=
s.<br><br></div>Doubling the block size is safer than halving the block int=
erval, for the same effect in aggregate transactions per second.<br></div><=
div class=3D"gmail_extra"><br><div class=3D"gmail_quote">On Fri, Aug 7, 201=
5 at 2:18 PM, Sergio Demian Lerner via bitcoin-dev <span dir=3D"ltr">&lt;<a=
 href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" target=3D"_blank">bi=
tcoin-dev@lists.linuxfoundation.org</a>&gt;</span> wrote:<br><blockquote cl=
ass=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;p=
adding-left:1ex"><div dir=3D"ltr">What would you do?<div><br></div><div>a. =
Double the block size</div><div>b. Reduce the block rate to a half (average=
 5 minute blocks)</div><div><br></div><div><div>Suppose this is a one time =
hard fork. There no drastic technical problems with any of them: &quot;SPV&=
quot; mining and the relay network has shown that block propagation is not =
an issue for such as small change. Mining centralization won&#39;t radicall=
y change for a 2x adjustment.=C2=A0</div><div><br></div><div>So what would =
be best for Bitcoin?</div></div><div><br></div><div>I suspect some (if not =
most of you) would choose b. Because reducing the block interval saves us r=
eal time. Waiting 30 minutes for a 3-block confirmation is... such a long t=
ime! Time that we value. Time that sometimes we waste waiting. Time that ma=
kes a difference for us. Doubling the block size does not change the user p=
erception of Bitcoin in any way.</div><div><br></div><div>Then why most dis=
cussions go around doubling the block size?<br></div><div><br></div><div><d=
iv>Each change require less than 20 lines of code (*) in the reference code=
, and minimum change in other wallets.=C2=A0</div><div><br></div><div>Curre=
ntly there is no idle mining hardware for hire, so the security of six 10-m=
inute block confirmation is equivalent to the security of six 5-minute bloc=
k confirmations, as described in Satoshi&#39;s paper (if there were 51% spa=
re mining hardware for hire, then obviously hiring that hardware for 30 min=
utes would cost less than hiring it for 1 hour).</div></div><div><br></div>=
<div>Why we discuss a 2x block size increase and not a 1/2 block interval r=
eduction? Aren&#39;t we Bitcoin users after all?</div><div><br></div><div>B=
est regards,</div><div>=C2=A0Sergio.</div><div><br></div><div>(*) b require=
s increasing the transaction version number, to support the old nLockTime r=
ate.<br></div><div><br></div><div><br></div></div>
<br>_______________________________________________<br>
bitcoin-dev mailing list<br>
<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org">bitcoin-dev@lists.=
linuxfoundation.org</a><br>
<a href=3D"https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev" =
rel=3D"noreferrer" target=3D"_blank">https://lists.linuxfoundation.org/mail=
man/listinfo/bitcoin-dev</a><br>
<br></blockquote></div><br></div>

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