From: Tamas Blummer <tamas.blummer@gmail.com>
Message-Id: <C6788578-80D4-44E7-8CF7-82AD15E3F12C@gmail.com>
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Date: Thu, 23 May 2019 21:18:06 +0200
In-Reply-To: <CAGNXQMTLjkC+i7YcVyWC0Z0ixTkwhYR2qF4R0qeMNTT4ntj9oQ@mail.gmail.com>
To: Nathan Cook <nathan.cook@gmail.com>
References: <CAD5xwhgHyR5qdd09ikvA_vgepj4o+Aqb0JA_T6FuqX56ZNe1RQ@mail.gmail.com>
	<42F53D61-BAAE-464F-BB0D-4D0CDC554D9A@gmail.com>
	<CAGNXQMTLjkC+i7YcVyWC0Z0ixTkwhYR2qF4R0qeMNTT4ntj9oQ@mail.gmail.com>
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] OP_DIFFICULTY to enable difficulty hedges (bets)
 without an oracle and 3rd party.
Precedence: list


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That opcode would not help as it fetches block hash and not the content =
of the header.

> On May 23, 2019, at 21:05, Nathan Cook <nathan.cook@gmail.com> wrote:
>=20
> You can get the same effect with OP_CHECKBLOCKATHEIGHT as proposed by =
Luke Dashjr =
(https://github.com/luke-jr/bips/blob/bip-cbah/bip-cbah.mediawiki =
<https://github.com/luke-jr/bips/blob/bip-cbah/bip-cbah.mediawiki>) if =
you also re-enable/extend certain opcodes like OP_AND and OP_LESSTHAN. =
See =
https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2016-September/013=
149.html =
<https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2016-September/01=
3149.html> and the ensuing thread.
>=20
> Nathan Cook
>=20
>=20
> On Thu, 23 May 2019 at 21:33, Tamas Blummer via bitcoin-dev =
<bitcoin-dev@lists.linuxfoundation.org =
<mailto:bitcoin-dev@lists.linuxfoundation.org>> wrote:
> Difficulty change has profound impact on miner=E2=80=99s production =
thereby introduce the biggest risk while considering an investment.
> Commodity markets offer futures and options to hedge risks on =
traditional trading venues. Some might soon list difficulty futures.
>=20
> I think we could do much better than them natively within Bitcoin.
>=20
> A better solution could be a transaction that uses nLocktime =
denominated in block height, such that it is valid after the difficulty =
adjusted block in the future.
> A new OP_DIFFICULTY opcode would put onto stack the value of =
difficulty for the block the transaction is included into.
> The output script may then decide comparing that value with a strike =
which key can spend it.
> The input of the transaction would be a multi-sig escrow of those who =
entered the bet.
> The winner would broadcast.
>=20
> Once signed by both the transaction would not carry any counterparty =
risk and would not need an oracle to settle according to the bet.
>=20
> I plan to draft a BIP for this as I think this opcode would serve =
significant economic interest of Bitcoin economy, and is compatible with =
Bitcoin=E2=80=99s aim not to introduce 3rd party to do so.
>=20
> Do you see a fault in this proposal or want to contribute?
>=20
> Tamas Blummer
>=20
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org =
<mailto:bitcoin-dev@lists.linuxfoundation.org>
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev =
<https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev>


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<html><head><meta http-equiv=3D"Content-Type" content=3D"text/html =
charset=3Dutf-8"></head><body style=3D"word-wrap: break-word; =
-webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" =
class=3D""><div class=3D"">That opcode would not help as it fetches =
block hash and not the content of the header.</div><br =
class=3D""><div><blockquote type=3D"cite" class=3D""><div class=3D"">On =
May 23, 2019, at 21:05, Nathan Cook &lt;<a =
href=3D"mailto:nathan.cook@gmail.com" =
class=3D"">nathan.cook@gmail.com</a>&gt; wrote:</div><br =
class=3D"Apple-interchange-newline"><div class=3D""><div dir=3D"ltr" =
class=3D"">You can get the same effect with OP_CHECKBLOCKATHEIGHT as =
proposed by Luke Dashjr (<a =
href=3D"https://github.com/luke-jr/bips/blob/bip-cbah/bip-cbah.mediawiki" =
target=3D"_blank" =
class=3D"">https://github.com/luke-jr/bips/blob/bip-cbah/bip-cbah.mediawik=
i</a>) if you also re-enable/extend certain opcodes like OP_AND and =
OP_LESSTHAN. See&nbsp;<a =
href=3D"https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2016-Septe=
mber/013149.html" =
class=3D"">https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2016-Se=
ptember/013149.html</a>&nbsp;and the ensuing thread.<div class=3D""><br =
clear=3D"all" class=3D""><div class=3D""><div dir=3D"ltr" =
class=3D"m_403880825204588202m_-2348348040253356886gmail_signature" =
data-smartmail=3D"gmail_signature">Nathan Cook</div></div><br =
class=3D""></div></div><br class=3D""><div class=3D"gmail_quote"><div =
dir=3D"ltr" class=3D"gmail_attr">On Thu, 23 May 2019 at 21:33, Tamas =
Blummer via bitcoin-dev &lt;<a =
href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" target=3D"_blank" =
class=3D"">bitcoin-dev@lists.linuxfoundation.org</a>&gt; wrote:<br =
class=3D""></div><blockquote class=3D"gmail_quote" style=3D"margin:0px =
0px 0px 0.8ex;border-left:1px solid =
rgb(204,204,204);padding-left:1ex">Difficulty change has profound impact =
on miner=E2=80=99s production thereby introduce the biggest risk while =
considering an investment.<br class=3D"">
Commodity markets offer futures and options to hedge risks on =
traditional trading venues. Some might soon list difficulty futures.<br =
class=3D"">
<br class=3D"">
I think we could do much better than them natively within Bitcoin.<br =
class=3D"">
<br class=3D"">
A better solution could be a transaction that uses nLocktime denominated =
in block height, such that it is valid after the difficulty adjusted =
block in the future.<br class=3D"">
A new OP_DIFFICULTY opcode would put onto stack the value of difficulty =
for the block the transaction is included into. <br class=3D"">
The output script may then decide comparing that value with a strike =
which key can spend it. <br class=3D"">
The input of the transaction would be a multi-sig escrow of those who =
entered the bet. <br class=3D"">
The winner would broadcast. <br class=3D"">
<br class=3D"">
Once signed by both the transaction would not carry any counterparty =
risk and would not need an oracle to settle according to the bet.<br =
class=3D"">
<br class=3D"">
I plan to draft a BIP for this as I think this opcode would serve =
significant economic interest of Bitcoin economy, and is compatible with =
Bitcoin=E2=80=99s aim not to introduce 3rd party to do so.<br class=3D"">
<br class=3D"">
Do you see a fault in this proposal or want to contribute?<br class=3D"">
<br class=3D"">
Tamas Blummer <br class=3D"">
<br class=3D"">
_______________________________________________<br class=3D"">
bitcoin-dev mailing list<br class=3D"">
<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" target=3D"_blank"=
 class=3D"">bitcoin-dev@lists.linuxfoundation.org</a><br class=3D"">
<a href=3D"https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev"=
 rel=3D"noreferrer" target=3D"_blank" =
class=3D"">https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev<=
/a><br class=3D"">
</blockquote></div>
</div></blockquote></div><br class=3D""></body></html>=

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