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Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Proof of Payment
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So at the low level, how does a "proof of payment" differ from just proving
that a given transaction is in a given block (what SPV nodes take as proof
of payment today)?
On Apr 27, 2015 2:42 PM, "Kalle Rosenbaum" <kalle@rosenbaum.se> wrote:
> "Or a really high lock_time, but it would not make it invalid, just
> delayed."
>
> Ok, this was a bad idea, since nodes would have to keep it in memory.
> Please disregard that idea...
>
> Kalle
>
> Den 27 apr 2015 14:35 skrev "Kalle Rosenbaum" <kalle@rosenbaum.se>:
> >
> > >
> > > Some more use cases might be:
> > > Waiting in comfort:
> > > - Send a payment ahead of time, then wander over and collect the goods
> > > after X confirmations.
> > >
> > > Authorized pickup :
> > > - Hot wallet software used by related people could facilitate the use
> > > of 1 of N multisig funds. Any one of the N wallets could collect goods
> > > and services purchased by any of the others.
> >
> > I like this one, because it shows the power of reusing the transaction
> data structure.
> >
> > >
> > > Non-monetary gifts:
> > > - Sender exports spent keys to a beneficiary, enabling PoP to work as
> a
> > > gift claim
> > >
> > > Contingent services:
> > > - Without Bob's permission, a 3rd party conditions action on a payment
> > > made from Alice to Bob. For example, if you donated at least .02 BTC
> to
> > > Dorian, you (or combining scenarios, any of your N authorized family
> > > members), can come to my dinner party.
> >
> > This is an interesting one.
> >
> > >
> > > I tried out your demo wallet and service and it worked as advertised.
> > >
> > > Could the same standard also be used to prove that a transaction COULD
> > > BE created? To generalize the concept beyond actual payments, you
> could
> > > call it something like proof of payment potential.
> >
> > I guess it's possible, but we'd have to remove the txid from the output,
> since there is none. This is a way of saying "I'm in control of these
> addresses". The other party/parties can then verify the funds on the
> blockchain and watch those addresses for changes. Maybe there are some
> interesting use cases here. Ideas?
> >
> > >
> > > Why not make these proofs permanently INVALID transactions, to remove
> > > any possibility of their being mined and spending everything to fees
> > > when used in this way, and also in cases involving reorganizations?
> >
> > Yes. Initially I thought it would be enough that the funds are already
> spent, but I think you're right here. Reorgs could be a problem. Worse, you
> also might want to prove 0-confirmation transactions, in which case it's a
> huge security problem. Someone might intercept the PoP and publish it on
> the bitcoin network, spending all the funds. But I still would like wallets
> to be able to build/verify PoPs with little or no modifications. Could we
> possibly change the version number on the PoP to something other than 1?
> Maybe 2^4-1? Or a really high lock_time, but it would not make it invalid,
> just delayed. Any suggestions here?
> >
> > >
> > > I agree that PoP seems complementary to BIP70.
> > >
> > >
> >
> > Thank you very much for your comments!
> >
> > /Kalle
>
>
> ------------------------------------------------------------------------------
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--f46d04182800ac7f620514c3be39
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
<p dir=3D"ltr">So at the low level, how does a "proof of payment"=
differ from just proving that a given transaction is in a given block (wha=
t SPV nodes take as proof of payment today)?</p>
<div class=3D"gmail_quote">On Apr 27, 2015 2:42 PM, "Kalle Rosenbaum&q=
uot; <<a href=3D"mailto:kalle@rosenbaum.se">kalle@rosenbaum.se</a>> w=
rote:<br type=3D"attribution"><blockquote class=3D"gmail_quote" style=3D"ma=
rgin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><p dir=3D"ltr"=
>"Or a really high lock_time, but it would not make it invalid, just d=
elayed." </p>
<p dir=3D"ltr">Ok, this was a bad idea, since nodes would have to keep it i=
n memory. Please disregard that idea... </p>
<p dir=3D"ltr">Kalle </p>
<p dir=3D"ltr">Den 27 apr 2015 14:35 skrev "Kalle Rosenbaum" <=
<a href=3D"mailto:kalle@rosenbaum.se" target=3D"_blank">kalle@rosenbaum.se<=
/a>>:<br>
><br>
> ><br>
> > Some more use cases might be:<br>
> > Waiting in comfort:<br>
> > =C2=A0- Send a payment ahead of time, then wander over and collec=
t the goods<br>
> > after X confirmations.<br>
> ><br>
> > Authorized pickup :<br>
> > =C2=A0- Hot wallet software used by related people could facilita=
te the use<br>
> > of 1 of N multisig funds.=C2=A0 Any one of the N wallets could co=
llect goods<br>
> > and services purchased by any of the others.<br>
><br>
> I like this one, because it shows the power of reusing the transaction=
data structure.<br>
><br>
> ><br>
> > Non-monetary gifts:<br>
> > =C2=A0- Sender exports spent keys to a beneficiary, enabling PoP =
to work as a<br>
> > gift claim<br>
> ><br>
> > Contingent services:<br>
> > =C2=A0- Without Bob's permission, a 3rd party conditions acti=
on on a payment<br>
> > made from Alice to Bob.=C2=A0 For example, if you donated at leas=
t .02 BTC to<br>
> > Dorian, you (or combining scenarios, any of your N authorized fam=
ily<br>
> > members), can come to my dinner party.<br>
><br>
> This is an interesting one.<br>
><br>
> ><br>
> > I tried out your demo wallet and service and it worked as adverti=
sed.<br>
> ><br>
> > Could the same standard also be used to prove that a transaction =
COULD<br>
> > BE created?=C2=A0 To generalize the concept beyond actual payment=
s, you could<br>
> > call it something like proof of payment potential.<br>
><br>
> I guess it's possible, but we'd have to remove the txid from t=
he output, since there is none. This is a way of saying "I'm in co=
ntrol of these addresses". The other party/parties can then verify the=
funds on the blockchain and watch those addresses for changes. Maybe there=
are some interesting use cases here. Ideas?<br>
><br>
> ><br>
> > Why not make these proofs permanently INVALID transactions, to re=
move<br>
> > any possibility of their being mined and spending everything to f=
ees<br>
> > when used in this way, and also in cases involving reorganization=
s?<br>
><br>
> Yes. Initially I thought it would be enough that the funds are already=
spent, but I think you're right here. Reorgs could be a problem. Worse=
, you also might want to prove 0-confirmation transactions, in which case i=
t's a huge security problem. Someone might intercept the PoP and publis=
h it on the bitcoin network, spending all the funds. But I still would like=
wallets to be able to build/verify PoPs with little or no modifications. C=
ould we possibly change the version number on the PoP to something other th=
an 1? Maybe 2^4-1? Or a really high lock_time, but it would not make it inv=
alid, just delayed. Any suggestions here?<br>
><br>
> ><br>
> > I agree that PoP seems complementary to BIP70.<br>
> ><br>
> ><br>
><br>
> Thank you very much for your comments!<br>
><br>
> /Kalle</p>
<br>-----------------------------------------------------------------------=
-------<br>
One dashboard for servers and applications across Physical-Virtual-Cloud<br=
>
Widest out-of-the-box monitoring support with 50+ applications<br>
Performance metrics, stats and reports that give you Actionable Insights<br=
>
Deep dive visibility with transaction tracing using APM Insight.<br>
<a href=3D"http://ad.doubleclick.net/ddm/clk/290420510;117567292;y" target=
=3D"_blank">http://ad.doubleclick.net/ddm/clk/290420510;117567292;y</a><br>=
_______________________________________________<br>
Bitcoin-development mailing list<br>
<a href=3D"mailto:Bitcoin-development@lists.sourceforge.net">Bitcoin-develo=
pment@lists.sourceforge.net</a><br>
<a href=3D"https://lists.sourceforge.net/lists/listinfo/bitcoin-development=
" target=3D"_blank">https://lists.sourceforge.net/lists/listinfo/bitcoin-de=
velopment</a><br>
<br></blockquote></div>
--f46d04182800ac7f620514c3be39--
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