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From: Paul Sztorc <truthcoin@gmail.com>
Date: Mon, 6 Nov 2017 15:30:30 -0500
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To: Peter Todd <pete@petertodd.org>,
Bitcoin Dev <bitcoin-dev@lists.linuxfoundation.org>
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Subject: Re: [bitcoin-dev] Introducing a POW through a soft-fork
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+1 to all of Peter Todd's comments
On Nov 6, 2017 11:50 AM, "Peter Todd via bitcoin-dev" <
bitcoin-dev@lists.linuxfoundation.org> wrote:
> On Wed, Nov 01, 2017 at 05:48:27AM +0000, Devrandom via bitcoin-dev wrote:
>
> Some quick thoughts...
>
> > Hi all,
> >
> > Feedback is welcome on the draft below. In particular, I want to see if
> > there is interest in further development of the idea and also interested
> in
> > any attack vectors or undesirable dynamics.
> >
> > (Formatted version available here:
> > https://github.com/devrandom/btc-papers/blob/master/aux-pow.md )
> >
> > # Soft-fork Introduction of a New POW
>
> First of all, I don't think you can really call this a soft-fork; I'd call
> it a
> "pseudo-soft-fork"
>
> My reasoning being that after implementation, a chain with less total work
> than
> the main chain - but more total SHA256^2 work than the main chain - might
> be
> followed by non-supporting clients. It's got some properties of a
> soft-fork,
> but it's security model is definitely different.
>
> > ### Aux POW intermediate block
> >
> > Auxiliary POW blocks are introduced between normal blocks - i.e. the
> chain
> > alternates between the two POWs.
> > Each aux-POW block points to the previous normal block and contains
> > transactions just like a normal block.
> > Each normal block points to the previous aux-POW block and must contain
> all
> > transactions from the aux-POW block.
>
> Note how you're basically proposing for the block interval to be decreased,
> which has security implications due to increased orphan rates.
>
> > ### Heaviest chain rule change
> >
> > This is a semi-hard change, because non-upgraded nodes can get on the
> wrong
> > chain in case of attack. However,
>
> Exactly! Not really a soft-fork.
>
> --
> https://petertodd.org 'peter'[:-1]@petertodd.org
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
>
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Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
<div dir=3D"auto">+1 to all of Peter Todd's comments</div><div class=3D=
"gmail_extra"><br><div class=3D"gmail_quote">On Nov 6, 2017 11:50 AM, "=
;Peter Todd via bitcoin-dev" <<a href=3D"mailto:bitcoin-dev@lists.l=
inuxfoundation.org">bitcoin-dev@lists.linuxfoundation.org</a>> wrote:<br=
type=3D"attribution"><blockquote class=3D"gmail_quote" style=3D"margin:0 0=
0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On Wed, Nov 01, 2017 a=
t 05:48:27AM +0000, Devrandom via bitcoin-dev wrote:<br>
<br>
Some quick thoughts...<br>
<br>
> Hi all,<br>
><br>
> Feedback is welcome on the draft below.=C2=A0 In particular, I want to=
see if<br>
> there is interest in further development of the idea and also interest=
ed in<br>
> any attack vectors or undesirable dynamics.<br>
><br>
> (Formatted version available here:<br>
> <a href=3D"https://github.com/devrandom/btc-papers/blob/master/aux-pow=
.md" rel=3D"noreferrer" target=3D"_blank">https://github.com/devrandom/<wbr=
>btc-papers/blob/master/aux-<wbr>pow.md</a> )<br>
><br>
> # Soft-fork Introduction of a New POW<br>
<br>
First of all, I don't think you can really call this a soft-fork; I'=
;d call it a<br>
"pseudo-soft-fork"<br>
<br>
My reasoning being that after implementation, a chain with less total work =
than<br>
the main chain - but more total SHA256^2 work than the main chain - might b=
e<br>
followed by non-supporting clients. It's got some properties of a soft-=
fork,<br>
but it's security model is definitely different.<br>
<br>
> ### Aux POW intermediate block<br>
><br>
> Auxiliary POW blocks are introduced between normal blocks - i.e. the c=
hain<br>
> alternates between the two POWs.<br>
> Each aux-POW block points to the previous normal block and contains<br=
>
> transactions just like a normal block.<br>
> Each normal block points to the previous aux-POW block and must contai=
n all<br>
> transactions from the aux-POW block.<br>
<br>
Note how you're basically proposing for the block interval to be decrea=
sed,<br>
which has security implications due to increased orphan rates.<br>
<br>
> ### Heaviest chain rule change<br>
><br>
> This is a semi-hard change, because non-upgraded nodes can get on the =
wrong<br>
> chain in case of attack.=C2=A0 However,<br>
<br>
Exactly! Not really a soft-fork.<br>
<br>
--<br>
<a href=3D"https://petertodd.org" rel=3D"noreferrer" target=3D"_blank">http=
s://petertodd.org</a> 'peter'[:-1]@<a href=3D"http://petertodd.org"=
rel=3D"noreferrer" target=3D"_blank">petertodd.org</a><br>
<br>______________________________<wbr>_________________<br>
bitcoin-dev mailing list<br>
<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org">bitcoin-dev@lists.=
<wbr>linuxfoundation.org</a><br>
<a href=3D"https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev" =
rel=3D"noreferrer" target=3D"_blank">https://lists.linuxfoundation.<wbr>org=
/mailman/listinfo/bitcoin-<wbr>dev</a><br>
<br></blockquote></div></div>
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