From: Tamas Blummer <tamas.blummer@gmail.com>
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Date: Thu, 23 May 2019 21:45:58 +0200
In-Reply-To: <CAGNXQMQG4KwAohfENYuUW=uABGshbJMYmdb_71ZtByCuj=14bQ@mail.gmail.com>
To: Nathan Cook <nathan.cook@gmail.com>
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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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I see. The uncompressing needs to be done either to compare. How are =
chances for that BIP?

This BIP would be explicitly offering risk managment of miners biggest =
risk.
Doing so without relying on external markets or oracle, self cointained =
would be an impressive and adequate feature.

Tamas Blummer

> On May 23, 2019, at 21:21, Nathan Cook <nathan.cook@gmail.com> wrote:
>=20
> It's true that it fetches the block hash; the idea is to compare the =
block hash's numeric value to the desired (uncompressed) difficulty =
directly, using a 256-bit version of OP_LESSTHAN.
>=20
> Nathan Cook
>=20
>=20
> On Thu, 23 May 2019 at 22:18, Tamas Blummer <tamas.blummer@gmail.com> =
wrote:
> That opcode would not help as it fetches block hash and not the =
content of the header.
>=20
>> 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) 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 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> 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
>> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>=20


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