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Date: Tue, 9 Jun 2015 14:25:18 -0400
Message-ID: <CABsx9T0TzRCr7DRzALymWiNJ2oA_MuZZQ8jFD+z4-cUaiSsE1A@mail.gmail.com>
From: Gavin Andresen <gavinandresen@gmail.com>
To: "Raystonn ." <raystonn@hotmail.com>
Content-Type: multipart/alternative; boundary=047d7b34391a69fb6e051819e1f9
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] New attack identified and potential
 solution described: Dropped-transaction spam attack against the block size
 limit
Precedence: list

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On Tue, Jun 9, 2015 at 1:52 PM, Raystonn . <raystonn@hotmail.com> wrote:

>   That does sound good on the surface, but how do we enforce #1 and #2?
> They seem to be unenforceable, as a miner can adjust the size of the memory
> pool in his local source.
>

It doesn't have to be enforced. As long as a reasonable percentage of hash
rate is following that policy an attacker that tries to flood the network
will fail to prevent normal transaction traffic from going through and will
just end up transferring some wealth to the miners.

Although the existing default mining policy (which it seems about 70% of
hashpower follows) of setting aside some space for high-priority
transactions regardless of fee might also be enough to cause this attack to
fail in practice.

-- 
--
Gavin Andresen

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<div dir=3D"ltr"><div class=3D"gmail_extra"><div class=3D"gmail_quote">On T=
ue, Jun 9, 2015 at 1:52 PM, Raystonn . <span dir=3D"ltr">&lt;<a href=3D"mai=
lto:raystonn@hotmail.com" target=3D"_blank">raystonn@hotmail.com</a>&gt;</s=
pan> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex=
;border-left:1px #ccc solid;padding-left:1ex">
<div dir=3D"ltr">
<div dir=3D"ltr">
<div style=3D"FONT-SIZE:10pt;FONT-FAMILY:&#39;Arial&#39;;COLOR:#000000">
<div>That does sound good on the surface, but how do we enforce #1 and #2?=
=C2=A0=20
They seem to be unenforceable, as a miner can adjust the size of the memory=
 pool=20
in his local source.</div></div></div></div></blockquote><div><br></div><di=
v>It doesn&#39;t have to be enforced. As long as a reasonable percentage of=
 hash rate is following that policy an attacker that tries to flood the net=
work will fail to prevent normal transaction traffic from going through and=
 will just end up transferring some wealth to the miners.</div><div><br></d=
iv><div>Although the existing default mining policy (which it seems about 7=
0% of hashpower follows) of setting aside some space for high-priority tran=
sactions regardless of fee might also be enough to cause this attack to fai=
l in practice.</div></div><div><br></div>-- <br><div class=3D"gmail_signatu=
re">--<br>Gavin Andresen<br></div><div class=3D"gmail_signature"><br></div>
</div></div>

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