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Date: Mon, 27 Apr 2015 14:41:51 +0200
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From: Kalle Rosenbaum <kalle@rosenbaum.se>
To: Tom Harding <tomh@thinlink.com>
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Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Proof of Payment
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"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
--001a1139b1b2fc047f0514b4115a
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
<p dir=3D"ltr">"Or a really high lock_time, but it would not make it i=
nvalid, just delayed." </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">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>
--001a1139b1b2fc047f0514b4115a--
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