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From: Johnson Lau <jl2012@xbt.hk>
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Date: Thu, 3 Nov 2016 11:35:02 +0800
References: <CAMZUoKkG0AqwsTE=opTcsD=xqWsoVxqPVCzFbcSz8zJT1wiFPg@mail.gmail.com>
To: Russell O'Connor <roconnor@blockstream.io>,
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Subject: Re: [bitcoin-dev] Implementing Covenants with
OP_CHECKSIGFROMSTACKVERIFY
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Interesting. I have implemented OP_CHECKSIGFROMSTACKVERIFY in a =
different way from the Elements. Instead of hashing the data on stack, I =
directly put the 32 byte hash to the stack. This should be more flexible =
as not every system are using double-SHA256
https://github.com/jl2012/bitcoin/commits/mast_v3_master =
<https://github.com/jl2012/bitcoin/commits/mast_v3_master>
> On 3 Nov 2016, at 01:30, Russell O'Connor via bitcoin-dev =
<bitcoin-dev@lists.linuxfoundation.org =
<mailto:bitcoin-dev@lists.linuxfoundation.org>> wrote:
>=20
> Hi all,
>=20
> It is possible to implement covenants using two script extensions: =
OP_CAT and OP_CHECKSIGFROMSTACKVERIFY. Both of these op codes are =
already available in the Elements Alpha sidechain, so it is possible to =
construct covenants in Elements Alpha today. I have detailed how the =
construction works in a blog post at =
<https://blockstream.com/2016/11/02/covenants-in-elements-alpha.html =
<https://blockstream.com/2016/11/02/covenants-in-elements-alpha.html>>. =
As an example, I've constructed scripts for the Moeser-Eyal-Sirer vault.
>=20
> I'm interested in collecting and implementing other useful covenants, =
so if people have ideas, please post them.
>=20
> If there are any questions, I'd be happy to answer. =20
>=20
> --=20
> Russell O'Connor
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org =
<mailto:bitcoin-dev@lists.linuxfoundation.org>
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
--Apple-Mail=_9770579C-3E4F-411D-844F-5E38B2FBFB11
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<html><head><meta http-equiv=3D"Content-Type" content=3D"text/html =
charset=3Dus-ascii"><meta http-equiv=3D"Content-Type" content=3D"text/html=
charset=3Dus-ascii"></head><body style=3D"word-wrap: break-word; =
-webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" =
class=3D""><div class=3D"">Interesting. I have =
implemented OP_CHECKSIGFROMSTACKVERIFY in a different way from the =
Elements. Instead of hashing the data on stack, I directly put the 32 =
byte hash to the stack. This should be more flexible as not every system =
are using double-SHA256</div><div class=3D""><br class=3D""></div><div =
class=3D""><a =
href=3D"https://github.com/jl2012/bitcoin/commits/mast_v3_master" =
class=3D"">https://github.com/jl2012/bitcoin/commits/mast_v3_master</a></d=
iv><div class=3D""><br class=3D""></div><br class=3D""><div><blockquote =
type=3D"cite" class=3D""><div class=3D"">On 3 Nov 2016, at 01:30, =
Russell O'Connor via bitcoin-dev <<a =
href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" =
class=3D"">bitcoin-dev@lists.linuxfoundation.org</a>> wrote:</div><br =
class=3D"Apple-interchange-newline"><div class=3D""><div dir=3D"ltr" =
class=3D"">Hi all,<br class=3D""><br class=3D"">It is possible to =
implement covenants using two script extensions: OP_CAT and =
OP_CHECKSIGFROMSTACKVERIFY. Both of these op codes are already =
available in the Elements Alpha sidechain, so it is possible to =
construct covenants in Elements Alpha today. I have detailed how =
the construction works in a blog post at <<a =
href=3D"https://blockstream.com/2016/11/02/covenants-in-elements-alpha.htm=
l" =
class=3D"">https://blockstream.com/2016/11/02/covenants-in-elements-alpha.=
html</a>>. As an example, I've constructed scripts for the =
Moeser-Eyal-Sirer vault.<br class=3D""><br class=3D"">I'm interested in =
collecting and implementing other useful covenants, so if people have =
ideas, please post them.<br class=3D""><br class=3D"">If there are any =
questions, I'd be happy to answer. <br class=3D""><br class=3D"">-- =
<br class=3D"">Russell O'Connor<br class=3D""></div>
_______________________________________________<br class=3D"">bitcoin-dev =
mailing list<br class=3D""><a =
href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" =
class=3D"">bitcoin-dev@lists.linuxfoundation.org</a><br class=3D""><a =
href=3D"https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev" =
class=3D"">https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev<=
/a><br class=3D""></div></blockquote></div><br class=3D""></body></html>=
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